Twine RNG Specification library

This library provides the necessary tools to build and validate twine-rng strands. It is intended to be used with the twine-rs library.

Example

Validation of a twine pair:

use twine_spec_rng::extract_randomness;

let current: Twine = ...;
let previous: Twine = ...;
let rand = extract_randomness(&current, &previous)?;

Building an rng strand.

Note: When building, timing is important. When the payload is built, it calculates the timestamp that the next tixel should be available. If it's late and takes longer to create than the period, the randomness extraction will fail when a client attempts to extract it.

use twine_protocol::{twine_builder::{RingSigner, TwineBuilder}, twine_lib::crypto::PublicKey};
use chrono::TimeDelta;
use twine_protocol::twine_lib::multihash_codetable::Code;
use twine_spec_rng::{PayloadBuilder, RngStrandDetails, subspec_string};

// create a new twine builder
let signer = RingSigner::generate_rs256(2048).unwrap();
let builder = TwineBuilder::new(signer);
// build the strand, specifying the subspec, hasher, and details
let strand = builder.build_strand()
 .subspec(subspec_string())
 .hasher(Code::Sha3_256)
 // specify the period for the strand
 .details(RngStrandDetails { period: TimeDelta::seconds(60) })
 .done()
 .unwrap();

// create a payload builder with the initial randomness
// here we use 32 bytes of 1s for the next randomness
let pb = PayloadBuilder::new([0u8; 32].to_vec(), [1u8; 32].to_vec());

// build the first tixel
let first = builder.build_first(strand)
 .build_payload_then_done(pb.builder())
 .unwrap();

// advance the payload with new randomness
let pb = pb.advance([2u8; 32].to_vec());
// build the next tixel
let second = builder.build_next(&first)
  .build_payload_then_done(pb.builder())
  .unwrap();

// ... continue