ali-raheem / consensus

Library to allow trustless generation of a shared random number, even if you are the only honest party.

Consensus

Small library for multiple parties to estbalish a shared random number. Even if you are the only honest party.

This version is not necessarily compatible with consensus-sodium which uses libsodium but both now use the blake2b-256 hash.

Algorithim

1. All parties pick a secret random number
2. Each party shares a hash of that random number
3. Each party reveals the random number
4. Each party ensures the hashes matches the revealed number
5. All the random numbers are bitwise XOR'd to produce a random number

Dependencies

• libtomcrypt due to extreme portability

Build

gcc -o bin/consensus_test src/test.c src/consensus.c -ltomcrypt

Can be built as a static library as usual and archived with tomcrypt.

Usage

See src/test.c, each party only generates one secret, disseminating the hash, and then the secret is left up to the user. For most applications you will want to process the secret for example hasing it.