ped92: add methods to CSParams

This commit is contained in:
Gijs Van Laer 2019-06-14 19:57:52 -04:00
parent 1f2e56bef2
commit 1195f0fdc2
1 changed files with 39 additions and 73 deletions

View File

@ -1,19 +1,7 @@
// commit_schemes.rs
extern crate serde;
use serialization_wrappers;
use std::fmt;
// ped92.rs
use rand::{thread_rng, Rng};
use bn::{Group, Fr, G1, G2};
use pairing::{Engine, CurveProjective, CurveAffine};
use ff::Rand;
use clsigs;
use debug_elem_in_hex;
use bincode::SizeLimit::Infinite;
use bincode::rustc_serialize::encode;
use sodiumoxide::crypto::hash::sha512;
use serde::{Serialize, Deserialize};
#[derive(Clone)]
pub struct PublicKey<E: Engine> {
@ -125,69 +113,47 @@ pub fn ped92_decommit<E: Engine>(pk: &PublicKey<E>, cm: &Commitment<E>, m: E::Fr
}
/*
Implements the setup algorithm for the Pedersen92 commitment scheme over
a vector of messages.
*/
pub fn setup<E: Engine>(len: usize, pub_bases: Vec<E::G2>, h: E::G2) -> CSParams<E> {
let rng = &mut thread_rng();
//let base_h = h.unwrap_or(G2::random(rng));
let mut p: Vec<E::G2> = Vec::new();
p.push(h);
let _p = pub_bases;
for i in 0.._p.len() {
p.push(_p[i]);
impl<E: Engine> CSParams<E> {
/*
Implements the setup algorithm for the Pedersen92 commitment scheme over
a vector of messages.
*/
pub fn setup_gen_params<R: Rng>(rng: &mut R, len: usize) -> Self {
let mut p: Vec<E::G2> = Vec::new();
for i in 0..len {
p.push(E::G2::rand(rng));
}
return CSParams { pub_bases: p };
}
return CSParams { pub_bases: p };
}
pub fn setup_gen_params<E: Engine>(len: usize) -> CSParams<E> {
let rng = &mut thread_rng();
let mut p: Vec<E::G2> = Vec::new();
for i in 0..len {
p.push(E::G2::rand(rng));
pub fn commit<R: Rng>(&self, rng: &mut R, x: &Vec<E::Fr>, r: E::Fr) -> Commitment<E> {
//let r = R.unwrap_or(Fr::random(rng));
// c = g1^m1 * ... * gn^mn * h^r
let mut c = self.pub_bases[0].clone();
c.mul_assign(r);
for i in 1..x.len() {
let mut basis = self.pub_bases[i];
basis.mul_assign(x[i]);
c.add_assign(&basis);
}
// return (c, r) <- r
Commitment { c, r }
}
return CSParams { pub_bases: p };
}
pub fn commit<E: Engine>(csp: &CSParams<E>, x: &Vec<E::Fr>, r: E::Fr) -> Commitment<E> {
let rng = &mut thread_rng();
//let r = R.unwrap_or(Fr::random(rng));
// c = g1^m1 * ... * gn^mn * h^r
//println!("(commit) index: 0");
let mut c = csp.pub_bases[0].clone();
c.mul_assign(r);
for i in 1..x.len() {
//println!("(commit) index: {}", i);
let mut basis = csp.pub_bases[i];
basis.mul_assign(x[i]);
c.add_assign(&basis);
pub fn decommit(&self, cm: &Commitment<E>, x: &Vec<E::Fr>) -> bool {
let l = x.len();
// pub_base[0] => h, x[0] => r
// check that cm.r == x[0]
let mut dc = self.pub_bases[0].clone();
dc.mul_assign(cm.r.clone());
for i in 1..l {
let mut basis = self.pub_bases[i];
basis.mul_assign(x[i]);
dc.add_assign(&basis);
}
return dc == cm.c && cm.r == x[0];
}
// return (c, r) <- r
let commitment = Commitment { c, r };
// debugging
//println!("{}", commitment);
return commitment;
}
pub fn decommit<E: Engine>(csp: &CSParams<E>, cm: &Commitment<E>, x: &Vec<E::Fr>) -> bool {
let l = x.len();
// pub_base[0] => h, x[0] => r
// check that cm.r == x[0]
// assert!(cm.r == x[0]);
let mut dc = csp.pub_bases[0].clone();
dc.mul_assign(cm.r.clone());
for i in 1..l {
let mut basis = csp.pub_bases[i];
basis.mul_assign(x[i]);
dc.add_assign(&basis);
}
return dc == cm.c && cm.r == x[0];
}
#[cfg(test)]
@ -215,15 +181,15 @@ mod tests {
fn commit_n_message_works() {
let rng = &mut thread_rng();
let len = 3;
let csp = setup_gen_params::<Bls12>(len);
let csp = CSParams::<Bls12>::setup_gen_params(rng, len);
let mut m: Vec<Fr> = Vec::new();
for i in 0..len {
m.push(Fr::rand(rng));
}
let r = m[0].clone();
let c = commit(&csp, &m, r);
let c = csp.commit(rng, &m, r);
assert_eq!(true, decommit(&csp, &c, &m));
assert_eq!(true, csp.decommit( &c, &m));
}
}