reorg and add matrix

Author: mhchia

README.md

@@ -111,6 +111,8 @@ Outline:
 - [x] NTT and polynomial multiplication
 - [x] Ajtai Commitment
 - [ ] Challenge spaces
+    - Fold challenge (Π^fold): ternary {-1,0,1} uniform (p=1/3 each). Maximises entropy for soundness. Not a strong subtractive set — SALSAA relies on large q making non-invertible differences negligible (~2^{-94} for q≈2^50). Ref: `salsaa/src/cyclotomic_ring.rs:319` (`random_biased`)
+    - JL projection (Π^{⊗RP}): ternary {-1,0,1} with p(0)=1/2, p(±1)=1/4 (two random bools). Only needs mean=0 + bounded variance for JL property. Sparser = faster. Ref: `salsaa/src/subroutines/project.rs:26` (`challenge_for_project`)
 - [ ] Sumcheck (over Rings)
 - [ ] MLE/LDE (over Rings)
 - [ ] Decomposition

src/ajtai.rs

@@ -1,6 +1,6 @@
 use rand::Rng;
 
-use super::poly::RqNtt;
+use super::ring::RqNtt;
 
 // Generate a random matrix (kappa x m) of Rq, in evaluation form.
 pub fn setup<const Q: u64, const D: usize>(
@@ -19,14 +19,6 @@ pub fn setup<const Q: u64, const D: usize>(
     mat
 }
 
-// def commit(A: vector, z: vector) -> vector:
-//     """
-//     A: k x m, random matrix from setup
-//     z: m x 1, witness
-
-//     return c = Az: k x 1
-//     """
-//     return A * z
 
 pub fn commit<const Q: u64, const D: usize>(
     a: &[Vec<RqNtt<Q, D>>],

src/lib.rs

@@ -1,4 +1,7 @@
 pub mod ajtai;
+pub mod mat;
 pub mod ntt;
 pub mod poly;
+pub mod ring;
+pub mod rok;
 pub mod zq;