https://github.com/cedoor/sparse-merkle-tree
Sparse Merkle tree implementation in TypeScript.
https://github.com/cedoor/sparse-merkle-tree
javascript merkle-tree smt sparse-merkle-tree typescript
Last synced: 2 months ago
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Sparse Merkle tree implementation in TypeScript.
- Host: GitHub
- URL: https://github.com/cedoor/sparse-merkle-tree
- Owner: cedoor
- License: mit
- Created: 2021-03-17T09:37:32.000Z (about 4 years ago)
- Default Branch: main
- Last Pushed: 2021-04-08T08:31:53.000Z (about 4 years ago)
- Last Synced: 2025-03-17T21:00:02.883Z (2 months ago)
- Topics: javascript, merkle-tree, smt, sparse-merkle-tree, typescript
- Language: TypeScript
- Homepage: https://smt.cedoor.dev
- Size: 707 KB
- Stars: 27
- Watchers: 2
- Forks: 4
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
- Code of conduct: code-of-conduct.md
Awesome Lists containing this project
README
Sparse Merkle tree
Sparse Merkle tree implementation in TypeScript.
A sparse Merkle tree (SMT) is a data structure useful for storing a key/value map where every leaf node of the tree contains the cryptographic hash of a key/value pair and every non leaf node contains the concatenated hashes of its child nodes. SMTs provides a secure and efficient verification of large data sets and they are often used in peer-to-peer technologies. This implementation is an optimized version of the traditional sparse Merkle tree and it is based on the concepts expressed in the papers and resources below.
**Notice**: this library is still not stable and therefore it must be used with care.
## References
1. Rasmus Dahlberg, Tobias Pulls and Roel Peeters. _Efficient Sparse Merkle Trees: Caching Strategies and Secure (Non-)Membership Proofs_. Cryptology ePrint Archive: Report 2016/683, 2016. https://eprint.iacr.org/2016/683.
2. Faraz Haider. _Compact sparse merkle trees_. Cryptology ePrint Archive: Report 2018/955, 2018. https://eprint.iacr.org/2018/955.
3. Jordi Baylina and Marta Bellés. _Sparse Merkle Trees_. https://docs.iden3.io/publications/pdfs/Merkle-Tree.pdf.
4. Vitalik Buterin Fichter. _Optimizing sparse Merkle trees_. https://ethresear.ch/t/optimizing-sparse-merkle-trees/3751.
---
## Table of Contents
- 🛠 [Install](#install)
- 📜 [API reference](#api-reference)
- 🔬 [Development](#development)
- [Rules](#scroll-rules)
- [Commits](https://github.com/cedoor/cedoor/tree/main/git#commits-rules)
- [Branches](https://github.com/cedoor/cedoor/tree/main/git#branch-rules)
- 🧾 [MIT License](https://github.com/cedoor/sparse-merkle-tree/blob/master/LICENSE)
- ☎️ [Contacts](#contacts)
- [Developers](#developers)
## Install
### npm or yarn
You can install utils package with npm:
```bash
npm i @cedoor/smt --save
```
or with yarn:
```bash
yarn add @cedoor/smt
```
### CDN
You can also load it using a `script` tap using [unpkg](https://unpkg.com/):
```html
```
or [JSDelivr](https://www.jsdelivr.com/):
```html
```
## API reference
- [Creating trees](#smt-new)
- [Adding entries](#smt-add)
- [Getting values](#smt-get)
- [Updating values](#smt-update)
- [Deleting entries](#smt-delete)
- [Creating proofs](#smt-create-proof)
- [Verifying proofs](#smt-verify-proof)
# **new SMT**(hash: _HashFunction_, bigNumbers?: _boolean_): _SMT_
```typescript
import { SMT, hexToDec } from "@cedoor/smt"
import { sha256 } from "js-sha256"
import { poseidon } from "circomlib"
// Hexadecimal hashes.
const hash = (childNodes: ChildNodes) => sha256(childNodes.join(""))
const tree = new SMT(hash)
// Big number hashes.
const hash2 = (childNodes: ChildNodes) => poseidon(childNodes)
const tree2 = new SMT(hash2, true)
console.log(tree.root) // 0
console.log(tree2.root) // 0n
```
# **add**(key: _string_ | _number_, value: _string_ | _number_): _void_
```typescript
tree.add("2b", "44") // Hexadecimal key/value.
tree.add("16", "78")
tree.add("d", "e7")
tree.add("10", "141")
tree.add("20", "340")
console.log(tree.root) // 31ee2a59741c9c32a32d8c7fafe461cca1ccaf5986c2d592586e3e6482a48645
```
# **get**(key: _string_ | _number_): _undefined_ | _string_
```typescript
const value = tree.get("16")
console.log(value) // 78
```
# **update**(key: _string_ | _number_, value: _string_ | _number_): _void_
```typescript
tree.update("16", "79")
const value = tree.get("16")
console.log(value) // 79
```
# **delete**(key: _string_ | _number_): _void_
```typescript
tree.delete("16")
const value = tree.get("16")
console.log(value) // undefined
```
# **createProof**(key: _string_ | _number_): _Proof_
```typescript
const membershipProof = tree.createProof("2b")
const nonMembershipProof = tree.createProof("16") // This key has been deleted.
console.log(membershipProof)
/*
{
entry: [ '2b', '44', '1' ],
matchingEntry: undefined,
sidenodes: [
'006a0ab15a212e0e0126b81e056b11576628b1ad80792403dbb3a90be2e71d64',
'f786ce5a843614d7da216d95c0087c1eb29244927feeeeeb658aa60cf124cd5e'
],
root: 'c3c023c84afc0a7bab1dbebcef5f7beaf3d6af4af98e8f481620dec052be7d0d',
membership: true
}
*/
console.log(nonMembershipProof)
/*
{
entry: [ '16' ],
matchingEntry: undefined,
sidenodes: [
'960f23d9fbb44241be53efb7c4d69ac129bb1cb9482dcb6789d3cc7e6de2de2b',
'2a1aef839e68d1bdf43c1b3b1ed9ef16c27162e8a175898c9ac64a679b0fc825'
],
root: 'c3c023c84afc0a7bab1dbebcef5f7beaf3d6af4af98e8f481620dec052be7d0d',
membership: false
}
*/
```
# **verifyProof**(proof: _Proof_): _boolean_
```typescript
console.log(tree.verifyProof(membershipProof)) // true
console.log(tree.verifyProof(nonMembershipProof)) // true
```
## Contacts
### Developers
- e-mail : [email protected]
- github : [@cedoor](https://github.com/cedoor)
- website : https://cedoor.dev