Mcl-wasm NPM | npm.io

A portable and fast pairing-based cryptography library for Node.js by WebAssembly

Abstract

see mcl

News

2023/Sep/08 improve the performance a little
2023/Aug/17 improve the invMod performance
2023/Jun/10 add share/recover functions of Fr, G1, G2 for secret sharing.
2022/May/08 fix get{X,Y,Z} and get_{a,b}.
2021/Dec/15 rewritten by TypeScript (Thanks to asa-taka)
2021/Nov/11 unify index.js of Node.js and browser (Thanks to Futa HIRAKOBA)
2021/Aug/28 improve performance of {G1,G2}::isValidOrder()
2021/Jun/22 add index.d.ts
2021/Mar/02 improve performance
2020/Nov/10 setup function has changed.
add mulVec(xVec, yVec) where xVec is an array of G1 or G2 and yVec is an array of Fr, which returns sum of xVec[i] yVec[i].
G1.setHashOf is compatible with hash-to-curve-09 BLS12381G1XMD:SHA-256_SSWU_RO
support only BN254, ZKSNARK, BLS12-381 to remove mcl_c512.js
add mcl.precomputedMillerLoop2 and mcl.precomputedMillerLoop2mixed

How to use

The version v0.6.0 breaks backward compatibility of the entry point.

Node.js : const mcl = require('mcl-wasm')
React : const mcl = require('mcl-wasm')
HTML : <script src="https://herumi.github.io/mcl-wasm/browser/mcl.js"></script>

for Node.js

node test/test.js

browser demo

ID-based encryption

usages

init

// Ethereum 2.0 spec mode
mcl.init(mcl.BLS12_381)
  .then(() => {
    mcl.setETHserialization(true) // Ethereum serialization
    mcl.setMapToMode(mcl.IRTF) // for G2.setHashOf(msg)
    ...
  })

string conversion

a = new mcl.Fr()
a.setStr('255') // set 255
a.setStr('0xff') // set 0xff = 255
a.setStr('ff', 16) // set ff as hex-string

a.getStr() // '255'
a.getStr(16) // 'ff'

serialization

// byte array serialization
b.deserialize(a.serialize()) // b.isEqualTo(a)
// hex string of serialization()
b.deserializeHexStr(a.serializeToHexStr())

// serialization like Ethereum 2.0 only for BLS12-381
mcl.setETHserialization(true)

deserialization

/*
  it is big cost to to verify the order
  call once after init() if you want to disable it
  cf. sub group problem
*/
mcl.verifyOrderG1(false)
mcl.verifyOrderG2(false)

see test.js

Secret Sharing

shareFr = (cVec: Fr[], id: Fr): Fr
shareG1 = (cVec: G1[], id: Fr): G1
shareG2 = (cVec: G2[], id: Fr): G2

Evaluate the value of the polynomial f(x) whose coefficients cVec[] are vec with x=id. Return f(id).

recoverFr = (idVec: Fr[], yVec: Fr[]): Fr
recoverG1 = (idVec: Fr[], yVec: G1[]): G1
recoverG2 = (idVec: Fr[], yVec: G2[]): G2

Recover the polynomial f(x) through the point (idVec[0], yVec[0]), (idVec[1], yVec[1]), ... and return f(0). Note that the order of arguments is reversed from that of the recover function in bls-eth-wasm.