Standard Ristretto255-SHA256 ciphersuite implemented with @privacyresearch/ed25519-ts

Implementation of the OPRF(Ristretto255, SHA256) ciphersuite from this Internet-Draft OPRF protocol. Tested using implementation of the VOPRF specification.

This is a direct port of the OPRF(Ristretto255, SHA256) ciphersuite in implementation of the VOPRF specification, allowing it to be used in other protocols.

Usage

Install:

yarn add @privacyresearch/generic-ciphersuite-r255s256

Create a ciphersuite object as follows.

import { ristretto255SHA512Ciphersuite } from '@privacyresearch/generic-ciphersuite-r255s256'

// The ciphersuite requires an implementation of the `Ed25519Type<IntType>` interface. We'll use
// @privacyresearch/ed25519-ts and JSBI for that. You will need to `yarn add jsbi @privacyresearch/ed25519-ts`
for this to work
import { makeED } from '@privacyresearch/ed25519-ts'
import JSBI from 'jsbi'

const ciphersuite = ristretto255SHA512Ciphersuite<JSBI>(ed, OPRFMode.Verified)

// Derive some keys
const seed = hexToBytes('a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3a3')
const skSm = hexToBytes('ac37d5850510299406ea8eb8fa226a7bfc2467a4b070d6c7bf667948b9600b00')
const pkSm = hexToBytes('0c0254e22063cae3e1bae02fb6fa20882664a117c0278eda6bda3372c0dd9860')

const { skS, pkS } = ciphersuite.GG.deriveKeyPair(seed)
const skSBytes = ciphersuite.GG.serializeScalar(skS)
const pkSBytes = ciphersuite.GG.serializeElement(pkS)

Now the ciphersuite object can be passed to consuming protocols.

License

(c) 2021 Privacy Research, LLC (https://privacyresearch.io), see LICENSE file.