https://github.com/htr-tech/vigenere-decoder
Decode / Bruteforce Vigenere cipher text just using the Flag Format!!
https://github.com/htr-tech/vigenere-decoder
caeser-cipher capture-the-flag cipher ciphertext crypto ctf ctf-challenges ctf-tools vigenere vigenere-cipher vigenere-decoder
Last synced: 2 months ago
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Decode / Bruteforce Vigenere cipher text just using the Flag Format!!
- Host: GitHub
- URL: https://github.com/htr-tech/vigenere-decoder
- Owner: htr-tech
- License: mit
- Created: 2023-09-13T18:01:43.000Z (about 2 years ago)
- Default Branch: master
- Last Pushed: 2024-11-23T17:02:46.000Z (11 months ago)
- Last Synced: 2025-04-15T01:11:34.274Z (7 months ago)
- Topics: caeser-cipher, capture-the-flag, cipher, ciphertext, crypto, ctf, ctf-challenges, ctf-tools, vigenere, vigenere-cipher, vigenere-decoder
- Language: Python
- Homepage:
- Size: 17.6 KB
- Stars: 30
- Watchers: 4
- Forks: 6
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
Vigenère Cipher Decoder
Decode / Bruteforce Vigenere cipher text using the Flag Format!!
#
### ~$ `time`
Script & Source
Time Taken
Brutes Each Char (example Dir)
60 Minutes
Vigenère Cipher Decoder (This)
0.484 Seconds
> `vigenere.py -c "RymJHS{XQ_MOWF_TTXU_DBHQBIZR?}" -t "CatCTF"`
#
### ~$ `cat usage.txt`:
- Simply **clone the repository**. Only python should be installed in your system.
```bash
$ git clone https://github.com/htr-tech/Vigenere-Decoder
$ cd Vigenere-Decoder
$ python vigenere.py
```
> Ouput (Interactive Menu)
```
_ _ _
| | | (_)
| | | |_ ____ ____ ____ ____ ____ ____
\ \/ /| |/ _ |/ _ ) _ \ / _ )/ ___) _ )
\ / | ( ( | ( (/ /| | | ( (/ /| | ( (/ /
\/ |_|\_|| |\____)_| |_|\____)_| \____)
(_____| @htr-tech
Input Cipher Text: RymJHS{XQ_MOWF_TTXU_DBHQBIZR?}
Known/Flag Format: CatCTF
Possible Key: python
Possible Flag: CatCTF{IS_THIS_EVEN_POSSIBLE?}
```
- You can also use **command line argument** to run this script.
```bash
usage: vigenere.py [-h] [-c CIPHER] [-t TEXT]
options:
-h, --help show this help message and exit
-c CIPHER, --cipher CIPHER
cipher text
-t TEXT, --text TEXT known text / flag format
```
#
### ~ $ `cat faq.txt`
- ### What is Vigenère Cipher:
Vigenère cipher is a polyalphabetic encryption algorithm. It is a method of encrypting alphabetic text using a series of different Caesar ciphers based on the letters of a keyword.
It is considered a stronger cipher than the Caesar cipher because it uses longer keys that allow the letters to be encrypted in multiple ways, making frequency analysis less effective.
- ### What does this script do?
This script allows you to decrypt a Vigenere cipher by providing the known part of the plaintext or flag format. It uses a Decoder class to decode the ciphered text with a given key, and a BruteForcer class to attempt to find the decryption key by comparing the flag format with the decrypted text. More details are commented inside the script.
- ### More to be added...
#
### ~$ `./social`:
