https://github.com/bobg/merkle

Merkle hash trees
https://github.com/bobg/merkle

Last synced: about 2 months ago
JSON representation

Merkle hash trees

• Host: GitHub
• URL: https://github.com/bobg/merkle
• Owner: bobg
• License: mit
• Created: 2018-10-13T15:25:10.000Z (about 6 years ago)
• Default Branch: master
• Last Pushed: 2024-07-10T15:21:35.000Z (5 months ago)
• Last Synced: 2024-07-31T20:48:40.233Z (5 months ago)
• Language: Go
• Homepage: https://godoc.org/github.com/bobg/merkle
• Size: 50.8 KB
• Stars: 16
• Watchers: 4
• Forks: 3
• Open Issues: 2
• Metadata Files:
  • Readme: Readme.md
  • License: LICENSE

Awesome Lists containing this project

• awesome-go - merkle - Space-efficient computation of Merkle root hashes and inclusion proofs. (Data Structures and Algorithms / Trees)
• awesome-go-extra - merkle - 10-13T15:25:10Z|2022-05-08T00:27:21Z| (Generators / Trees)

README

        
# Merkle - Efficient calculation of merkle roots and proofs

[![Go Reference](https://pkg.go.dev/badge/github.com/bobg/merkle.svg)](https://pkg.go.dev/github.com/bobg/merkle)

[![Go Report Card](https://goreportcard.com/badge/github.com/bobg/merkle)](https://goreportcard.com/report/github.com/bobg/merkle)

[![Tests](https://github.com/bobg/merkle/actions/workflows/go.yml/badge.svg)](https://github.com/bobg/merkle/actions/workflows/go.yml)

[![Coverage Status](https://coveralls.io/repos/github/bobg/merkle/badge.svg?branch=master)](https://coveralls.io/github/bobg/merkle?branch=master)

[![Mentioned in Awesome Go](https://awesome.re/mentioned-badge.svg)](https://github.com/avelino/awesome-go)

This is merkle,

a Go package for computing the Merkle root hash of a sequence of byte strings,

or of their hashes.

It can also produce a compact proof that a given string belongs in a Merkle tree with a given root hash.

This implementation does not require holding all of the input in memory while computing a root hash or a proof.

Instead, it is able to operate on a stream of input strings of unbounded length,

holding incremental state that is only logarithmic [O(log N)] in the size of the input.

For more about Merkle trees,

see [the Wikipedia article](https://en.wikipedia.org/wiki/Merkle_tree).

Creating a merkle root hash:

```go

var ch <-chan []byte  // Represents some source of byte strings

tree := merkle.NewTree(sha256.New())

for str := range ch {

  tree.Add(str)

}

fmt.Printf("merkle root hash is %x\n", tree.Root())

```

Creating a merkle proof that `ref` belongs in the tree,

then verifying the proof:

```go

var (

  ch       <-chan []byte  // Represents some source of byte strings

  rootHash []byte         // Represents a previously computed merkle root hash (held by someone wishing to verify that ref is in the tree)

  ref      []byte         // Represents the string to prove is a member of the tree with the given root hash

)

tree := merkle.NewProofTree(sha256.New(), ref)

for str := range ch {

  tree.Add(str)

}

proof := tree.Proof()  // This is a compact object. For verification purposes, tree can now be discarded.

// Verification:

if bytes.Equal(rootHash, proof.Hash(sha256.New(), ref)) {

  fmt.Println("Verified!")

}

```