Start of full rewrite of rlwe crate

rlwe/src/encryption.rs

@@ -0,0 +1,71 @@
+use base2k::{
+    AddNormal, Backend, FillUniform, Module, VecZnxDftOps, ScalarZnxDftOps, ScalarZnxDftToRef, VecZnxBigOps, Scratch, VecZnx, VecZnxToMut, VecZnxToRef, ZnxInfos, FFT64
+};
+
+use sampling::source::Source;
+
+use crate::{
+    elem::{CipherVecZnx, Plaintext},
+    keys::SecretKey,
+};
+
+pub trait EncryptSk<B: Backend, D> {
+    fn encrypt<P, S>(
+        module: &Module<B>,
+        res: &mut D,
+        pt: Option<&Plaintext<P>>,
+        sk: &SecretKey<S>,
+        source_xa: &mut Source,
+        source_xe: &mut Source,
+        scratch: &mut Scratch,
+        sigma: f64,
+        bound: f64,
+    ) where
+        P: VecZnxToRef,
+        S: ScalarZnxDftToRef<B>;
+}
+
+impl<C> EncryptSk<FFT64, CipherVecZnx<C>> for CipherVecZnx<C>
+where
+    VecZnx<C>: VecZnxToMut + VecZnxToRef,
+{
+    fn encrypt<P, S>(
+        module: &Module<FFT64>,
+        ct: &mut CipherVecZnx<C>,
+        pt: Option<&Plaintext<P>>,
+        sk: &SecretKey<S>,
+        source_xa: &mut Source,
+        source_xe: &mut Source,
+        scratch: &mut Scratch,
+        sigma: f64,
+        bound: f64,
+    ) where
+        P: VecZnxToRef,
+        S: ScalarZnxDftToRef<FFT64>,
+    {
+        let log_base2k: usize = ct.log_base2k();
+        let log_q: usize = ct.log_q();
+        let mut ct_mut: VecZnx<&mut [u8]> = ct.data_mut().to_mut();
+        let size: usize = ct_mut.size();
+
+        ct_mut.fill_uniform(log_base2k, 1, size, source_xa);
+
+        // c1_dft = DFT(a) * DFT(s)
+        let (mut c1_dft, scratch_1) = scratch.tmp_vec_znx_dft(module, 1, size);
+        module.svp_apply(&mut c1_dft, 0, &sk.data().to_ref(), 0, &ct_mut, 1);
+
+        // c1_big = IDFT(c1_dft)
+        let (mut c1_big, scratch_2) = scratch_1.tmp_vec_znx_big(module, 1, size);
+        module.vec_znx_idft_tmp_a(&mut c1_big, 0, &mut c1_dft, 0);
+
+        // c1_big = m - c1_big
+        if let Some(pt) = pt {
+            module.vec_znx_big_sub_small_b_inplace(&mut c1_big, 0, &pt.data().to_ref(), 0);
+        }
+        // c1_big += e
+        c1_big.add_normal(log_base2k, 0, log_q, source_xe, sigma, bound);
+
+        // c0 = norm(c1_big)
+        module.vec_znx_big_normalize(log_base2k, &mut ct_mut, 0, &c1_big, 0, scratch_2);
+    }
+}