Refactor PRG to single impl

README.md

@@ -28,11 +28,11 @@ use rand::prelude::*;
 // Matyas-Meyer-Oseas (via AES128) provides 128-bit security and should be enough.
 // Hirose (via AES256) still only provides 128-bit security because the output is not chained.
 // But Hirose can be helpful is you are forced to choose AES256.
-use fss_rs::dcf::prg::Aes128MatyasMeyerOseasPrg;
+use fss_rs::prg::Aes128MatyasMeyerOseasPrg;
 use fss_rs::dcf::{Dcf, DcfImpl};
 
 let keys: [[u8; 32]; 2] = thread_rng().gen();
-let prg = Aes128MatyasMeyerOseasPrg::<16, 2>::new(std::array::from_fn(|i| &keys[i]));
+let prg = Aes128MatyasMeyerOseasPrg::<16, 2, 2>::new(std::array::from_fn(|i| &keys[i]));
 // DCF for example
 let dcf = DcfImpl::<16, 16, _>::new(prg);
 ```

benches/dcf_eval.rs

@@ -4,10 +4,10 @@
 use criterion::{criterion_group, criterion_main, BenchmarkId, Criterion};
 use rand::prelude::*;
 
-use fss_rs::dcf::prg::Aes128MatyasMeyerOseasPrg;
 use fss_rs::dcf::{BoundState, CmpFn, Dcf, DcfImpl};
 use fss_rs::group::byte::ByteGroup;
 use fss_rs::group::Group;
+use fss_rs::prg::Aes128MatyasMeyerOseasPrg;
 
 fn from_domain_range_size<const IN_BLEN: usize, const OUT_BLEN: usize, const CIPHER_N: usize>(
     c: &mut Criterion,
@@ -16,7 +16,7 @@ fn from_domain_range_size<const IN_BLEN: usize, const OUT_BLEN: usize, const CIP
     keys.iter_mut().for_each(|k| thread_rng().fill_bytes(k));
     let keys_iter = std::array::from_fn(|i| &keys[i]);
 
-    let prg = Aes128MatyasMeyerOseasPrg::<OUT_BLEN, CIPHER_N>::new(keys_iter);
+    let prg = Aes128MatyasMeyerOseasPrg::<OUT_BLEN, 2, CIPHER_N>::new(keys_iter);
     let dcf = DcfImpl::<IN_BLEN, OUT_BLEN, _>::new(prg);
 
     let mut s0s = [[0; OUT_BLEN]; 2];

benches/dcf_eval_batch.rs

@@ -4,10 +4,10 @@
 use criterion::{criterion_group, criterion_main, BenchmarkId, Criterion};
 use rand::prelude::*;
 
-use fss_rs::dcf::prg::Aes128MatyasMeyerOseasPrg;
 use fss_rs::dcf::{BoundState, CmpFn, Dcf, DcfImpl};
 use fss_rs::group::byte::ByteGroup;
 use fss_rs::group::Group;
+use fss_rs::prg::Aes128MatyasMeyerOseasPrg;
 
 const POINT_NUM: usize = 10000;
 
@@ -18,7 +18,7 @@ fn from_domain_range_size<const IN_BLEN: usize, const OUT_BLEN: usize, const CIP
     keys.iter_mut().for_each(|k| thread_rng().fill_bytes(k));
     let keys_iter = std::array::from_fn(|i| &keys[i]);
 
-    let prg = Aes128MatyasMeyerOseasPrg::<OUT_BLEN, CIPHER_N>::new(keys_iter);
+    let prg = Aes128MatyasMeyerOseasPrg::<OUT_BLEN, 2, CIPHER_N>::new(keys_iter);
     let dcf = DcfImpl::<IN_BLEN, OUT_BLEN, _>::new(prg);
 
     let mut s0s = [[0; OUT_BLEN]; 2];

benches/dcf_full_eval.rs

@@ -4,10 +4,10 @@
 use criterion::{criterion_group, criterion_main, BenchmarkId, Criterion};
 use rand::prelude::*;
 
-use fss_rs::dcf::prg::Aes128MatyasMeyerOseasPrg;
 use fss_rs::dcf::{BoundState, CmpFn, Dcf, DcfImpl};
 use fss_rs::group::byte::ByteGroup;
 use fss_rs::group::Group;
+use fss_rs::prg::Aes128MatyasMeyerOseasPrg;
 
 fn from_domain_range_size<const IN_BLEN: usize, const OUT_BLEN: usize, const CIPHER_N: usize>(
     c: &mut Criterion,
@@ -17,7 +17,7 @@ fn from_domain_range_size<const IN_BLEN: usize, const OUT_BLEN: usize, const CIP
     keys.iter_mut().for_each(|k| thread_rng().fill_bytes(k));
     let keys_iter = std::array::from_fn(|i| &keys[i]);
 
-    let prg = Aes128MatyasMeyerOseasPrg::<OUT_BLEN, CIPHER_N>::new(keys_iter);
+    let prg = Aes128MatyasMeyerOseasPrg::<OUT_BLEN, 2, CIPHER_N>::new(keys_iter);
     let dcf = DcfImpl::<IN_BLEN, OUT_BLEN, _>::new_with_filter(prg, filter_bitn);
 
     let mut s0s = [[0; OUT_BLEN]; 2];

benches/dcf_gen.rs

@@ -4,9 +4,9 @@
 use criterion::{criterion_group, criterion_main, BenchmarkId, Criterion};
 use rand::prelude::*;
 
-use fss_rs::dcf::prg::Aes128MatyasMeyerOseasPrg;
 use fss_rs::dcf::{BoundState, CmpFn, Dcf, DcfImpl};
 use fss_rs::group::byte::ByteGroup;
+use fss_rs::prg::Aes128MatyasMeyerOseasPrg;
 
 fn from_domain_range_size<const IN_BLEN: usize, const OUT_BLEN: usize, const CIPHER_N: usize>(
     c: &mut Criterion,
@@ -15,7 +15,7 @@ fn from_domain_range_size<const IN_BLEN: usize, const OUT_BLEN: usize, const CIP
     keys.iter_mut().for_each(|k| thread_rng().fill_bytes(k));
     let keys_iter = std::array::from_fn(|i| &keys[i]);
 
-    let prg = Aes128MatyasMeyerOseasPrg::<OUT_BLEN, CIPHER_N>::new(keys_iter);
+    let prg = Aes128MatyasMeyerOseasPrg::<OUT_BLEN, 2, CIPHER_N>::new(keys_iter);
     let dcf = DcfImpl::<IN_BLEN, OUT_BLEN, _>::new(prg);
 
     let mut s0s = [[0; OUT_BLEN]; 2];

benches/dpf_eval.rs

@@ -4,10 +4,10 @@
 use criterion::{criterion_group, criterion_main, BenchmarkId, Criterion};
 use rand::prelude::*;
 
-use fss_rs::dpf::prg::Aes128MatyasMeyerOseasPrg;
 use fss_rs::dpf::{Dpf, DpfImpl, PointFn};
 use fss_rs::group::byte::ByteGroup;
 use fss_rs::group::Group;
+use fss_rs::prg::Aes128MatyasMeyerOseasPrg;
 
 fn from_domain_range_size<const IN_BLEN: usize, const OUT_BLEN: usize, const CIPHER_N: usize>(
     c: &mut Criterion,
@@ -16,7 +16,7 @@ fn from_domain_range_size<const IN_BLEN: usize, const OUT_BLEN: usize, const CIP
     keys.iter_mut().for_each(|k| thread_rng().fill_bytes(k));
     let keys_iter = std::array::from_fn(|i| &keys[i]);
 
-    let prg = Aes128MatyasMeyerOseasPrg::<OUT_BLEN, CIPHER_N>::new(keys_iter);
+    let prg = Aes128MatyasMeyerOseasPrg::<OUT_BLEN, 1, CIPHER_N>::new(keys_iter);
     let dpf = DpfImpl::<IN_BLEN, OUT_BLEN, _>::new(prg);
 
     let mut s0s = [[0; OUT_BLEN]; 2];

benches/dpf_eval_batch.rs

@@ -4,10 +4,10 @@
 use criterion::{criterion_group, criterion_main, BenchmarkId, Criterion};
 use rand::prelude::*;
 
-use fss_rs::dpf::prg::Aes128MatyasMeyerOseasPrg;
 use fss_rs::dpf::{Dpf, DpfImpl, PointFn};
 use fss_rs::group::byte::ByteGroup;
 use fss_rs::group::Group;
+use fss_rs::prg::Aes128MatyasMeyerOseasPrg;
 
 const POINT_NUM: usize = 10000;
 
@@ -18,7 +18,7 @@ fn from_domain_range_size<const IN_BLEN: usize, const OUT_BLEN: usize, const CIP
     keys.iter_mut().for_each(|k| thread_rng().fill_bytes(k));
     let keys_iter = std::array::from_fn(|i| &keys[i]);
 
-    let prg = Aes128MatyasMeyerOseasPrg::<OUT_BLEN, CIPHER_N>::new(keys_iter);
+    let prg = Aes128MatyasMeyerOseasPrg::<OUT_BLEN, 1, CIPHER_N>::new(keys_iter);
     let dpf = DpfImpl::<IN_BLEN, OUT_BLEN, _>::new(prg);
 
     let mut s0s = [[0; OUT_BLEN]; 2];

benches/dpf_full_eval.rs

@@ -4,10 +4,10 @@
 use criterion::{criterion_group, criterion_main, BenchmarkId, Criterion};
 use rand::prelude::*;
 
-use fss_rs::dpf::prg::Aes128MatyasMeyerOseasPrg;
 use fss_rs::dpf::{Dpf, DpfImpl, PointFn};
 use fss_rs::group::byte::ByteGroup;
 use fss_rs::group::Group;
+use fss_rs::prg::Aes128MatyasMeyerOseasPrg;
 
 fn from_domain_range_size<const IN_BLEN: usize, const OUT_BLEN: usize, const CIPHER_N: usize>(
     c: &mut Criterion,
@@ -17,7 +17,7 @@ fn from_domain_range_size<const IN_BLEN: usize, const OUT_BLEN: usize, const CIP
     keys.iter_mut().for_each(|k| thread_rng().fill_bytes(k));
     let keys_iter = std::array::from_fn(|i| &keys[i]);
 
-    let prg = Aes128MatyasMeyerOseasPrg::<OUT_BLEN, CIPHER_N>::new(keys_iter);
+    let prg = Aes128MatyasMeyerOseasPrg::<OUT_BLEN, 1, CIPHER_N>::new(keys_iter);
     let dpf = DpfImpl::<IN_BLEN, OUT_BLEN, _>::new_with_filter(prg, filter_bitn);
 
     let mut s0s = [[0; OUT_BLEN]; 2];

benches/dpf_gen.rs

@@ -4,9 +4,9 @@
 use criterion::{criterion_group, criterion_main, BenchmarkId, Criterion};
 use rand::prelude::*;
 
-use fss_rs::dpf::prg::Aes128MatyasMeyerOseasPrg;
 use fss_rs::dpf::{Dpf, DpfImpl, PointFn};
 use fss_rs::group::byte::ByteGroup;
+use fss_rs::prg::Aes128MatyasMeyerOseasPrg;
 
 fn from_domain_range_size<const IN_BLEN: usize, const OUT_BLEN: usize, const CIPHER_N: usize>(
     c: &mut Criterion,
@@ -15,7 +15,7 @@ fn from_domain_range_size<const IN_BLEN: usize, const OUT_BLEN: usize, const CIP
     keys.iter_mut().for_each(|k| thread_rng().fill_bytes(k));
     let keys_iter = std::array::from_fn(|i| &keys[i]);
 
-    let prg = Aes128MatyasMeyerOseasPrg::<OUT_BLEN, CIPHER_N>::new(keys_iter);
+    let prg = Aes128MatyasMeyerOseasPrg::<OUT_BLEN, 1, CIPHER_N>::new(keys_iter);
     let dpf = DpfImpl::<IN_BLEN, OUT_BLEN, _>::new(prg);
 
     let mut s0s = [[0; OUT_BLEN]; 2];

src/dcf/mod.rs

@@ -9,10 +9,7 @@ use rayon::prelude::*;
 
 use crate::group::Group;
 use crate::utils::{xor, xor_inplace};
-use crate::{decl_prg_trait, Cw, PointFn, Share};
-
-#[cfg(feature = "prg")]
-pub mod prg;
+use crate::{Cw, PointFn, Prg, Share};
 
 /// Distributed comparison function API.
 ///
@@ -64,22 +61,20 @@ where
     }
 }
 
-decl_prg_trait!(([u8; OUT_BLEN], [u8; OUT_BLEN], bool));
-
 /// [`Dcf`] impl.
 ///
 /// `$\alpha$` itself is not included (or say exclusive endpoint), which means `$f(\alpha)$ = 0`.
 pub struct DcfImpl<const IN_BLEN: usize, const OUT_BLEN: usize, P>
 where
-    P: Prg<OUT_BLEN>,
+    P: Prg<OUT_BLEN, 2>,
 {
     prg: P,
     filter_bitn: usize,
 }
 
 impl<const IN_BLEN: usize, const OUT_BLEN: usize, P> DcfImpl<IN_BLEN, OUT_BLEN, P>
 where
-    P: Prg<OUT_BLEN>,
+    P: Prg<OUT_BLEN, 2>,
 {
     pub fn new(prg: P) -> Self {
         Self {
@@ -100,7 +95,7 @@ const IDX_R: usize = 1;
 impl<const IN_BLEN: usize, const OUT_BLEN: usize, P, G> Dcf<IN_BLEN, OUT_BLEN, G>
     for DcfImpl<IN_BLEN, OUT_BLEN, P>
 where
-    P: Prg<OUT_BLEN>,
+    P: Prg<OUT_BLEN, 2>,
     G: Group<OUT_BLEN>,
 {
     fn gen(
@@ -119,8 +114,8 @@ where
         for i in 0..n {
             // MSB is required since we index from high to low in arrays.
             let alpha_i = f.alpha.view_bits::<Msb0>()[i];
-            let [(s0l, v0l, t0l), (s0r, v0r, t0r)] = self.prg.gen(&ss_prev[0]);
-            let [(s1l, v1l, t1l), (s1r, v1r, t1r)] = self.prg.gen(&ss_prev[1]);
+            let [([s0l, v0l], t0l), ([s0r, v0r], t0r)] = self.prg.gen(&ss_prev[0]);
+            let [([s1l, v1l], t1l), ([s1r, v1r], t1r)] = self.prg.gen(&ss_prev[1]);
             // MSB is required since we index from high to low in arrays.
             let (keep, lose) = if alpha_i {
                 (IDX_R, IDX_L)
@@ -201,7 +196,7 @@ where
 
 impl<const IN_BLEN: usize, const OUT_BLEN: usize, P> DcfImpl<IN_BLEN, OUT_BLEN, P>
 where
-    P: Prg<OUT_BLEN>,
+    P: Prg<OUT_BLEN, 2>,
 {
     /// Eval with single-threading.
     /// See [`Dcf::eval`].
@@ -255,7 +250,7 @@ where
 
         let cw = &k.cws[layer_i];
         // `*_hat` before in-place XOR.
-        let [(mut sl, vl_hat, mut tl), (mut sr, vr_hat, mut tr)] = self.prg.gen(&s);
+        let [([mut sl, vl_hat], mut tl), ([mut sr, vr_hat], mut tr)] = self.prg.gen(&s);
         xor_inplace(&mut sl, &[if t { &cw.s } else { &[0; OUT_BLEN] }]);
         xor_inplace(&mut sr, &[if t { &cw.s } else { &[0; OUT_BLEN] }]);
         tl ^= t & cw.tl;
@@ -291,7 +286,7 @@ where
         for i in 0..n {
             let cw = &k.cws[i];
             // `*_hat` before in-place XOR.
-            let [(mut sl, vl_hat, mut tl), (mut sr, vr_hat, mut tr)] = self.prg.gen(&s_prev);
+            let [([mut sl, vl_hat], mut tl), ([mut sr, vr_hat], mut tr)] = self.prg.gen(&s_prev);
             xor_inplace(&mut sl, &[if t_prev { &cw.s } else { &[0; OUT_BLEN] }]);
             xor_inplace(&mut sr, &[if t_prev { &cw.s } else { &[0; OUT_BLEN] }]);
             tl ^= t_prev & cw.tl;
@@ -326,9 +321,9 @@ pub enum BoundState {
 mod tests {
     use rand::prelude::*;
 
-    use super::prg::Aes256HirosePrg;
     use super::*;
     use crate::group::byte::ByteGroup;
+    use crate::prg::Aes256HirosePrg;
 
     const KEYS: &[&[u8; 32]] = &[
         b"j9\x1b_\xb3X\xf33\xacW\x15\x1b\x0812K\xb3I\xb9\x90r\x1cN\xb5\xee9W\xd3\xbb@\xc6d",
@@ -345,7 +340,7 @@ mod tests {
 
     #[test]
     fn test_dcf_gen_then_eval() {
-        let prg = Aes256HirosePrg::<16, 2>::new(std::array::from_fn(|i| KEYS[i]));
+        let prg = Aes256HirosePrg::<16, 2, 2>::new(std::array::from_fn(|i| KEYS[i]));
         let dcf = DcfImpl::<16, 16, _>::new(prg);
         let s0s: [[u8; 16]; 2] = thread_rng().gen();
         let f = CmpFn {
@@ -377,7 +372,7 @@ mod tests {
 
     #[test]
     fn test_dcf_gen_gt_beta_then_eval() {
-        let prg = Aes256HirosePrg::<16, 2>::new(std::array::from_fn(|i| KEYS[i]));
+        let prg = Aes256HirosePrg::<16, 2, 2>::new(std::array::from_fn(|i| KEYS[i]));
         let dcf = DcfImpl::<16, 16, _>::new(prg);
         let s0s: [[u8; 16]; 2] = thread_rng().gen();
         let f = CmpFn {
@@ -409,7 +404,7 @@ mod tests {
 
     #[test]
     fn test_dcf_gen_then_eval_with_filter() {
-        let prg = Aes256HirosePrg::<16, 2>::new(std::array::from_fn(|i| KEYS[i]));
+        let prg = Aes256HirosePrg::<16, 2, 2>::new(std::array::from_fn(|i| KEYS[i]));
         let dcf = DcfImpl::<16, 16, _>::new_with_filter(prg, 127);
         let s0s: [[u8; 16]; 2] = thread_rng().gen();
         let f = CmpFn {
@@ -441,7 +436,7 @@ mod tests {
 
     #[test]
     fn test_dcf_gen_then_eval_not_zeros() {
-        let prg = Aes256HirosePrg::<16, 2>::new(std::array::from_fn(|i| KEYS[i]));
+        let prg = Aes256HirosePrg::<16, 2, 2>::new(std::array::from_fn(|i| KEYS[i]));
         let dcf = DcfImpl::<16, 16, _>::new(prg);
         let s0s: [[u8; 16]; 2] = thread_rng().gen();
         let f = CmpFn {
@@ -465,7 +460,7 @@ mod tests {
     #[test]
     fn test_dcf_full_eval() {
         let x: [u8; 2] = ALPHAS[2][..2].try_into().unwrap();
-        let prg = Aes256HirosePrg::<16, 2>::new(std::array::from_fn(|i| KEYS[i]));
+        let prg = Aes256HirosePrg::<16, 2, 2>::new(std::array::from_fn(|i| KEYS[i]));
         let dcf = DcfImpl::<2, 16, _>::new(prg);
         let s0s: [[u8; 16]; 2] = thread_rng().gen();
         let f = CmpFn {
@@ -491,7 +486,7 @@ mod tests {
     #[test]
     fn test_dcf_full_eval_with_filter() {
         let x: [u8; 2] = ALPHAS[2][..2].try_into().unwrap();
-        let prg = Aes256HirosePrg::<16, 2>::new(std::array::from_fn(|i| KEYS[i]));
+        let prg = Aes256HirosePrg::<16, 2, 2>::new(std::array::from_fn(|i| KEYS[i]));
         let dcf = DcfImpl::<2, 16, _>::new_with_filter(prg, 15);
         let s0s: [[u8; 16]; 2] = thread_rng().gen();
         let f = CmpFn {