Crate vdf

Rust implementations of class groups and verifyable delay functions

This repo includes three crates

• classgroup, which includes a class group implementation, as well as a trait for class groups.
• vdf, which includes a Verifyable Delay Function (VDF) trait, as well as an implementation of that trait.
• vdf-cli, which includes a command-line interface to the vdf crate. It also includes additional commands, which are deprecated and will later be replaced by a CLI to the classgroup crate.

Usage

First, install Rust, Cargo, and the GNU Multiprecision Library (GMP). Then, follow one of the below steps.

To use the command line interface

$ git clone https://github.com/poanetwork/vdf
$ cd vdf
$ cargo install
$ vdf-cli aa 100
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
$ vdf-cli aa 100 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
Proof is valid

To use the VDF library

extern crate vdf;
use vdf::{InvalidProof, PietrzakVDFParams, VDFParams, WesolowskiVDFParams, VDF};
const CORRECT_SOLUTION: &[u8] =
    b"\x00\x52\x71\xe8\xf9\xab\x2e\xb8\xa2\x90\x6e\x85\x1d\xfc\xb5\x54\x2e\x41\x73\xf0\x16\
    \xb8\x5e\x29\xd4\x81\xa1\x08\xdc\x82\xed\x3b\x3f\x97\x93\x7b\x7a\xa8\x24\x80\x11\x38\
    \xd1\x77\x1d\xea\x8d\xae\x2f\x63\x97\xe7\x6a\x80\x61\x3a\xfd\xa3\x0f\x2c\x30\xa3\x4b\
    \x04\x0b\xaa\xaf\xe7\x6d\x57\x07\xd6\x86\x89\x19\x3e\x5d\x21\x18\x33\xb3\x72\xa6\xa4\
    \x59\x1a\xbb\x88\xe2\xe7\xf2\xf5\xa5\xec\x81\x8b\x57\x07\xb8\x6b\x8b\x2c\x49\x5c\xa1\
    \x58\x1c\x17\x91\x68\x50\x9e\x35\x93\xf9\xa1\x68\x79\x62\x0a\x4d\xc4\xe9\x07\xdf\x45\
    \x2e\x8d\xd0\xff\xc4\xf1\x99\x82\x5f\x54\xec\x70\x47\x2c\xc0\x61\xf2\x2e\xb5\x4c\x48\
    \xd6\xaa\x5a\xf3\xea\x37\x5a\x39\x2a\xc7\x72\x94\xe2\xd9\x55\xdd\xe1\xd1\x02\xae\x2a\
    \xce\x49\x42\x93\x49\x2d\x31\xcf\xf2\x19\x44\xa8\xbc\xb4\x60\x89\x93\x06\x5c\x9a\x00\
    \x29\x2e\x8d\x3f\x46\x04\xe7\x46\x5b\x4e\xee\xfb\x49\x4f\x5b\xea\x10\x2d\xb3\x43\xbb\
    \x61\xc5\xa1\x5c\x7b\xdf\x28\x82\x06\x88\x5c\x13\x0f\xa1\xf2\xd8\x6b\xf5\xe4\x63\x4f\
    \xdc\x42\x16\xbc\x16\xef\x7d\xac\x97\x0b\x0e\xe4\x6d\x69\x41\x6f\x9a\x9a\xce\xe6\x51\
    \xd1\x58\xac\x64\x91\x5b";

fn main() {
    let pietrzak_vdf = PietrzakVDFParams(2048).new();
    assert_eq!(
        &pietrzak_vdf.solve(b"\xaa", 100).unwrap()[..],
        CORRECT_SOLUTION
    );
    assert!(pietrzak_vdf.verify(b"\xaa", 100, CORRECT_SOLUTION).is_ok());
}

To run the benchmarks

Benchmarks are provided for the classgroup operations. Run cargo bench to run them. Additional benchmarks are under development.

Structs

InvalidIterations

An error return indicating an invalid number of iterations. The string is a human-readable message describing the valid iterations. It should not be interpreted by programs.

InvalidProof

An empty struct indicating verification failure.

PietrzakVDF

PietrzakVDFParams

WesolowskiVDF

WesolowskiVDFParams

Traits

VDF

A Verifiable Delay Function (VDF).

VDFParams

The type of VDF parameters.

Functions

create_discriminant

Create a discriminant from a seed (a byte string) and a bit length (a u16). The discriminant is guaranteed to be a negative prime number that fits in length bits, except with negligible probability (less than 2^(-100)). It is also guaranteed to equal 7 modulo 8.