Schnorrrb Build Status Gem Version MIT License

This is a Ruby implementation of the Schnorr signature scheme over the elliptic curve. This implementation relies on the ecdsa gem for operate elliptic curves.

The code is based upon the initial proposal of Pieter Wuille's bip-schnorr.

Installation

Add this line to your application's Gemfile:

gem 'schnorr'

And then execute:

$ bundle

Or install it yourself as:

$ gem install schnorr

Usage

Singing

require 'schnorr'

private_key = 0xB7E151628AED2A6ABF7158809CF4F3C762E7160F38B4DA56A784D9045190CFEF

message = ['5E2D58D8B3BCDF1ABADEC7829054F90DDA9805AAB56C77333024B9D0A508B75C'].pack('H*')

# create signature
signature = Schnorr.sign(message, private_key)

# signature r value
signature.r 

# signature s value
signature.s 

# convert signature to binary

signature.encode

Verification

require 'schnorr'

public_key = ['03FAC2114C2FBB091527EB7C64ECB11F8021CB45E8E7809D3C0938E4B8C0E5F84B'].pack('H*')

signature = [`00DA9B08172A9B6F0466A2DEFD817F2D7AB437E0D253CB5395A963866B3574BE00880371D01766935B92D2AB4CD5C8A2A5837EC57FED7660773A05F0DE142380`].pack('H*')

message = ['5E2D58D8B3BCDF1ABADEC7829054F90DDA9805AAB56C77333024B9D0A508B75C'].pack('H*')

# verify signature.(result is true or false)
result = Schnorr.valid_sig?(message, public_key, signature) 

# signature convert to Signature object
sig = Schnorr::Signature.decode(signature)

Change elliptic curve

This library use secp256k1 curve as default. If you use another curve, you need to specify curve as following:

Schnorr.sign(message, private_key, group: ECDSA::Group::xxx)

Schnorr.valid_sig?(message, public_key, signature, group: ECDSA::Group::xxx)

Note: But this library has only been tested with secp256k1. So another curve are not tested.

TODO

The following is unimplemented now.

  • batch verification.
  • MuSig