fixed gadget product & related example

rlwe/src/ciphertext.rs

@@ -48,7 +48,7 @@ impl Ciphertext {
         self.0.log_scale
     }
 
-    pub fn zero(&mut self){
+    pub fn zero(&mut self) {
         self.0.zero()
     }
 

rlwe/src/decryptor.rs

@@ -1,5 +1,9 @@
 use crate::{
-    ciphertext::{Ciphertext, GadgetCiphertext}, elem::Elem, keys::SecretKey, parameters::Parameters, plaintext::Plaintext
+    ciphertext::{Ciphertext, GadgetCiphertext},
+    elem::Elem,
+    keys::SecretKey,
+    parameters::Parameters,
+    plaintext::Plaintext,
 };
 use base2k::{Module, SvpPPol, SvpPPolOps, VecZnxDft};
 use std::cmp::min;
@@ -46,26 +50,24 @@ pub fn decrypt_rlwe_thread_safe(
     sk: &SvpPPol,
     tmp_bytes: &mut [u8],
 ) {
-    let limbs: usize = min(res.limbs(), a.limbs());
-
     assert!(
-        tmp_bytes.len() >= decrypt_rlwe_thread_safe_tmp_byte(module, limbs),
+        tmp_bytes.len() >= decrypt_rlwe_thread_safe_tmp_byte(module, a.limbs()),
         "invalid tmp_bytes: tmp_bytes.len()={} < decrypt_rlwe_thread_safe_tmp_byte={}",
         tmp_bytes.len(),
-        decrypt_rlwe_thread_safe_tmp_byte(module, limbs)
+        decrypt_rlwe_thread_safe_tmp_byte(module, a.limbs())
     );
 
-    let res_dft_bytes: usize = module.bytes_of_vec_znx_dft(limbs);
+    let res_dft_bytes: usize = module.bytes_of_vec_znx_dft(a.limbs());
 
-    let mut res_dft: VecZnxDft = VecZnxDft::from_bytes(limbs, tmp_bytes);
+    let mut res_dft: VecZnxDft = VecZnxDft::from_bytes(a.limbs(), tmp_bytes);
     let mut res_big: base2k::VecZnxBig = res_dft.as_vec_znx_big();
 
     // res_dft <- DFT(ct[1]) * DFT(sk)
-    module.svp_apply_dft(&mut res_dft, sk, &a.value[1], limbs);
+    module.svp_apply_dft(&mut res_dft, sk, &a.value[1], a.limbs());
     // res_big <- ct[1] x sk
-    module.vec_znx_idft_tmp_a(&mut res_big, &mut res_dft, limbs);
+    module.vec_znx_idft_tmp_a(&mut res_big, &mut res_dft, a.limbs());
     // res_big <- ct[1] x sk + ct[0]
-    module.vec_znx_big_add_small_inplace(&mut res_big, &a.value[0], limbs);
+    module.vec_znx_big_add_small_inplace(&mut res_big, &a.value[0]);
     // res <- normalize(ct[1] x sk + ct[0])
     module.vec_znx_big_normalize(
         a.log_base2k(),

rlwe/src/elem.rs

@@ -91,7 +91,7 @@ impl Elem {
         &mut self.value[i]
     }
 
-    pub fn zero(&mut self){
+    pub fn zero(&mut self) {
         self.value.iter_mut().for_each(|i| i.zero());
     }
 }

rlwe/src/encryptor.rs

@@ -175,7 +175,7 @@ pub fn encrypt_rlwe_sk_thread_safe(
     }
 
     // c0 <- -s x c1 + m + e
-    //c0.add_normal(log_base2k, log_q, source_xe, sigma, (sigma * 6.0).ceil());
+    c0.add_normal(log_base2k, log_q, source_xe, sigma, (sigma * 6.0).ceil());
 }
 
 pub fn encrypt_grlwe_sk_tmp_bytes(
@@ -245,6 +245,7 @@ pub fn encrypt_grlwe_sk_thread_safe(
         // Zeroes the ith-row of tmp_pt
         tmp_pt.0.value[0].at_mut(row_i).fill(0);
 
+        /*
         let mut res: Elem = Elem::new(module, log_base2k, log_q, 0, tmp_elem.log_scale);
 
         decrypt_rlwe_thread_safe(module, &mut res, &tmp_elem, sk, tmp_bytes_encrypt_sk);
@@ -252,6 +253,7 @@ pub fn encrypt_grlwe_sk_thread_safe(
         println!("row:{}", row_i);
         res.value[0].print_limbs(res.limbs(), 16);
         println!();
+         */
 
         // GRLWE[row_i][0] = -as + m * 2^{-i*log_base2k} + e*2^{-log_q}
         module.vmp_prepare_row(

rlwe/src/evaluator.rs

@@ -1,5 +1,8 @@
-use crate::ciphertext::{Ciphertext, GadgetCiphertext};
-use base2k::{Module, VecZnxBig, VecZnxDft, VmpPMatOps};
+use crate::{
+    ciphertext::{Ciphertext, GadgetCiphertext},
+    elem::Elem,
+};
+use base2k::{Infos, Module, VecZnx, VecZnxBig, VecZnxDft, VmpPMatOps};
 
 pub fn gadget_product_tmp_bytes(
     module: &Module,
@@ -16,34 +19,27 @@ pub fn gadget_product_tmp_bytes(
         + 2 * module.bytes_of_vec_znx_dft(gct_cols)
 }
 
-pub fn gadget_product_inplace_thread_safe(
-    module: &Module,
-    a: &mut Ciphertext,
-    b: &GadgetCiphertext,
-    tmp_bytes: &mut [u8],
-) {
-    // This is safe to do because the relevant values of a are copied to a buffer before being
-    // overwritten.
-    unsafe {
-        let a_ptr: *mut Ciphertext = a;
-        gadget_product_thread_safe(module, a, &*a_ptr, b, tmp_bytes)
-    }
-}
-
+/// Evaluates the gadget product res <- a x b.
+///
+/// # Arguments
+///
+/// * `module`: backend support for operations mod (X^N + 1)
+/// * `res`: an [Elem] to store (-cs + m * a + e, c) with res_ncols limbs.
+/// * `a`: a [VecZnx] of a_ncols limbs.
+/// * `b`: a [GadgetCiphertext] as a vector of (-Bs + m * 2^{-k} + E, B)
+///       containing b_nrows [VecZnx], each of b_ncols limbs.
+///
+/// # Computation
+///
+/// res = sum[min(a_ncols, b_nrows)] decomp(a, i) * (-B[i]s + m * 2^{-k*i} + E[i], B[i])
+///     = (cs + m * a + e, c) with min(res_limbs, b_cols) limbs.
 pub fn gadget_product_thread_safe(
     module: &Module,
-    res: &mut Ciphertext,
-    a: &Ciphertext,
+    res: &mut Elem,
+    a: &VecZnx,
     b: &GadgetCiphertext,
     tmp_bytes: &mut [u8],
 ) {
-    assert!(
-        a.log_base2k() == b.log_base2k(),
-        "invalid inputs: a.log_base2k={} != b.log_base2k={}",
-        a.log_base2k(),
-        b.log_base2k()
-    );
-
     let log_base2k: usize = b.log_base2k();
     let cols: usize = b.cols();
 
@@ -57,7 +53,7 @@ pub fn gadget_product_thread_safe(
     let mut res_big: VecZnxBig = res_dft.as_vec_znx_big();
 
     // c1_dft <- DFT(c1) [cols]
-    module.vec_znx_dft(&mut c1_dft, a.at(1), a.limbs());
+    module.vec_znx_dft(&mut c1_dft, a, a.limbs());
 
     // res_dft <- sum[rows] DFT(c1)[cols] x GadgetCiphertext[0][cols]
     module.vmp_apply_dft_to_dft(&mut res_dft, &c1_dft, &b.value[0], tmp_bytes_vmp_apply_dft);
@@ -65,9 +61,6 @@ pub fn gadget_product_thread_safe(
     // res_big <- IDFT(DFT(c1) x GadgetCiphertext[0])
     module.vec_znx_idft_tmp_a(&mut res_big, &mut res_dft, cols);
 
-    // res_big <- c0 + c1_dft x GadgetCiphertext[0]
-    module.vec_znx_big_add_small_inplace(&mut res_big, a.at(0), cols);
-
     // res[0] = normalize(c0 + c1_dft x GadgetCiphertext[0])
     module.vec_znx_big_normalize(log_base2k, res.at_mut(0), &res_big, tmp_bytes_vmp_apply_dft);
 

rlwe/src/keys.rs

@@ -65,19 +65,19 @@ impl SwitchingKey {
         SwitchingKey(GadgetCiphertext::new(module, log_base2k, rows, log_q))
     }
 
-    pub fn n(&self) -> usize{
+    pub fn n(&self) -> usize {
         self.0.n()
     }
 
-    pub fn rows(&self) -> usize{
+    pub fn rows(&self) -> usize {
         self.0.rows()
     }
 
-    pub fn cols(&self) -> usize{
+    pub fn cols(&self) -> usize {
         self.0.cols()
     }
 
-    pub fn log_base2k(&self) -> usize{
+    pub fn log_base2k(&self) -> usize {
         self.0.log_base2k()
     }
 }

rlwe/src/plaintext.rs

@@ -64,7 +64,7 @@ impl Plaintext {
         self.0.log_scale()
     }
 
-    pub fn zero(&mut self){
+    pub fn zero(&mut self) {
         self.0.zero()
     }