working GGSW key-switch + added test (missing noise formula)

core/src/ggsw_ciphertext.rs

@@ -1,7 +1,7 @@
 use base2k::{
-    Backend, FFT64, MatZnxDft, MatZnxDftAlloc, MatZnxDftOps, MatZnxDftToMut, MatZnxDftToRef, Module, ScalarZnx, ScalarZnxDft,
-    ScalarZnxDftToRef, ScalarZnxToRef, Scratch, VecZnxAlloc, VecZnxBigOps, VecZnxDftAlloc, VecZnxDftOps, VecZnxDftToMut,
-    VecZnxDftToRef, VecZnxOps, ZnxInfos, ZnxZero,
+    Backend, FFT64, MatZnxDft, MatZnxDftAlloc, MatZnxDftOps, MatZnxDftScratch, MatZnxDftToMut, MatZnxDftToRef, Module, ScalarZnx,
+    ScalarZnxDft, ScalarZnxDftToRef, ScalarZnxToRef, Scratch, VecZnxAlloc, VecZnxBigAlloc, VecZnxBigOps, VecZnxBigScratch,
+    VecZnxDftAlloc, VecZnxDftOps, VecZnxDftToMut, VecZnxDftToRef, VecZnxOps, ZnxInfos, ZnxZero,
 };
 use sampling::source::Source;
 
@@ -81,6 +81,27 @@ impl GGSWCiphertext<Vec<u8>, FFT64> {
             + module.bytes_of_vec_znx_dft(rank + 1, size)
     }
 
+    pub fn keyswitch_scratch_space(
+        module: &Module<FFT64>,
+        out_size: usize,
+        in_size: usize,
+        ksk_size: usize,
+        tsk_size: usize,
+        rank: usize,
+    ) -> usize {
+        let tmp_dft_out: usize = module.bytes_of_vec_znx_dft(rank + 1, out_size);
+        let vmp_ksk: usize = module.bytes_of_vec_znx_dft(rank + 1, in_size)
+            + GLWECiphertextFourier::keyswitch_scratch_space(module, out_size, rank, in_size, rank, ksk_size);
+        let tmp_c0: usize = module.bytes_of_vec_znx_big(1, out_size);
+        let tmp_dft_i: usize = module.bytes_of_vec_znx_dft(rank + 1, tsk_size);
+        let vmp_tsk: usize = module.bytes_of_vec_znx_dft(1, out_size)
+            + module.vmp_apply_tmp_bytes(out_size, out_size, rank + 1, rank + 1, rank + 1, tsk_size);
+        let tmp_idft: usize = module.bytes_of_vec_znx_big(1, tsk_size);
+        let tmp_znx_small: usize = module.bytes_of_vec_znx(1, out_size);
+        let norm: usize = module.vec_znx_big_normalize_tmp_bytes();
+        tmp_dft_out + (vmp_ksk | (tmp_c0 + tmp_dft_i + (vmp_tsk | (tmp_idft + tmp_znx_small + norm))))
+    }
+
     pub fn automorphism_scratch_space(
         module: &Module<FFT64>,
         out_size: usize,
@@ -90,7 +111,8 @@ impl GGSWCiphertext<Vec<u8>, FFT64> {
     ) -> usize {
         let tmp_dft: usize = module.bytes_of_vec_znx_dft(rank + 1, auto_key_size);
         let tmp_idft: usize = module.bytes_of_vec_znx(rank + 1, out_size);
-        let vmp: usize = GLWECiphertext::keyswitch_from_fourier_scratch_space(module, out_size, rank, in_size, rank, auto_key_size);
+        let vmp: usize =
+            GLWECiphertext::keyswitch_from_fourier_scratch_space(module, out_size, rank, in_size, rank, auto_key_size);
         tmp_dft + tmp_idft + vmp
     }
 
@@ -198,7 +220,6 @@ where
         });
     }
 
-
     pub fn keyswitch<DataLhs, DataRhs0, DataRhs1>(
         &mut self,
         module: &Module<FFT64>,
@@ -257,7 +278,6 @@ where
         // col 2: (-(c0s0' + c1s1' + c2s2')    , c0    , c1 + M, c2    )
         // col 3: (-(d0s0' + d1s1' + d2s2')    , d0    , d1    , d2 + M)
         (0..self.rows()).for_each(|row_j| {
-
             let (tmp_dft_out_data, scratch1) = scratch.tmp_vec_znx_dft(module, self.rank() + 1, self.size());
 
             let mut tmp_dft_out: GLWECiphertextFourier<&mut [u8], FFT64> = GLWECiphertextFourier::<&mut [u8], FFT64> {
@@ -291,7 +311,6 @@ where
             // col 2: (-(c0s0' + c1s1' + c2s2')    , c0       , c1 + M[i], c2       ) = KS_{s1's0', s1's1', s1's2'}(a1) + (0, 0, -(a0s0' + a1s1' + a2s2') + M[i], 0)
             // col 3: (-(d0s0' + d1s1' + d2s2')    , d0       , d1       , d2 + M[i]) = KS_{s2's0', s2's1', s2's2'}(a2) + (0, 0, 0, -(a0s0' + a1s1' + a2s2') + M[i])
             (1..cols).for_each(|col_i| {
-
                 let (tmp_dft_i_data, scratch3) = scratch2.tmp_vec_znx_dft(module, cols, tsk.size());
                 let mut tmp_dft_i: GLWECiphertextFourier<&mut [u8], FFT64> = GLWECiphertextFourier::<&mut [u8], FFT64> {
                     data: tmp_dft_i_data,
@@ -311,7 +330,6 @@ where
                 // =
                 // (-(x0s0' + x1s1' + x2s2') + s0'(a0s0' + a1s1' + a2s2'), x0, x1, x2)
                 (1..cols).for_each(|col_j| {
-
                     // Extracts a[i] and multipies with Enc(s'[i]s'[j])
                     let (mut tmp_dft_col_data, scratch4) = scratch3.tmp_vec_znx_dft(module, 1, self.size());
                     tmp_dft_col_data.extract_column(0, &tmp_dft_out.data, col_j);
@@ -347,7 +365,9 @@ where
                     let (mut tmp_znx_small, scratch5) = scratch3.tmp_vec_znx(module, 1, self.size());
                     (0..cols).for_each(|i| {
                         module.vec_znx_idft_tmp_a(&mut tmp_idft, 0, &mut tmp_dft_i, i);
-                        module.vec_znx_big_add_inplace(&mut tmp_idft, col_i, &tmp_c0_data, 0);
+                        if i == col_i {
+                            module.vec_znx_big_add_inplace(&mut tmp_idft, 0, &tmp_c0_data, 0);
+                        }
                         module.vec_znx_big_normalize(self.basek(), &mut tmp_znx_small, 0, &tmp_idft, 0, scratch5);
                         module.vec_znx_dft(&mut tmp_dft_i, i, &tmp_znx_small, 0);
                     });
@@ -385,8 +405,7 @@ where
                 self.rank(),
                 rhs.rank()
             );
-        }
-;
+        };
         let cols: usize = self.rank() + 1;
 
         let (tmp_dft_data, scratch1) = scratch.tmp_vec_znx_dft(module, cols, rhs.size()); //TODO optimize

core/src/test_fft64/ggsw.rs

@@ -12,6 +12,8 @@ use crate::{
     glwe_plaintext::GLWEPlaintext,
     keys::{SecretKey, SecretKeyFourier},
     keyswitch_key::GLWESwitchingKey,
+    tensor_key::TensorKey,
+    test_fft64::gglwe::noise_gglwe_product,
 };
 
 #[test]
@@ -105,6 +107,139 @@ fn test_encrypt_sk(log_n: usize, basek: usize, k_ggsw: usize, sigma: f64, rank:
     });
 }
 
+#[test]
+fn keyswitch() {
+    (1..4).for_each(|rank| {
+        println!("test keyswitch rank: {}", rank);
+        test_keyswitch(12, 15, 60, rank, 3.2);
+    });
+}
+
+fn test_keyswitch(log_n: usize, basek: usize, k: usize, rank: usize, sigma: f64) {
+    let module: Module<FFT64> = Module::<FFT64>::new(1 << log_n);
+    let rows: usize = (k + basek - 1) / basek;
+
+    let mut ct_in: GGSWCiphertext<Vec<u8>, FFT64> = GGSWCiphertext::new(&module, basek, k, rows, rank);
+    let mut ct_out: GGSWCiphertext<Vec<u8>, FFT64> = GGSWCiphertext::new(&module, basek, k, rows, rank);
+    let mut tsk: TensorKey<Vec<u8>, FFT64> = TensorKey::new(&module, basek, k, rows, rank);
+    let mut ksk: GLWESwitchingKey<Vec<u8>, FFT64> = GLWESwitchingKey::new(&module, basek, k, rows, rank, rank);
+    let mut pt_have: GLWEPlaintext<Vec<u8>> = GLWEPlaintext::new(&module, basek, k);
+    let mut pt_want: GLWEPlaintext<Vec<u8>> = GLWEPlaintext::new(&module, basek, k);
+    let mut pt_scalar: ScalarZnx<Vec<u8>> = module.new_scalar_znx(1);
+
+    let mut source_xs: Source = Source::new([0u8; 32]);
+    let mut source_xe: Source = Source::new([0u8; 32]);
+    let mut source_xa: Source = Source::new([0u8; 32]);
+
+    let mut scratch: ScratchOwned = ScratchOwned::new(
+        GGSWCiphertext::encrypt_sk_scratch_space(&module, rank, ct_in.size())
+            | GLWECiphertextFourier::decrypt_scratch_space(&module, ct_out.size())
+            | GLWESwitchingKey::encrypt_sk_scratch_space(&module, rank, ksk.size())
+            | TensorKey::encrypt_sk_scratch_space(&module, rank, ksk.size())
+            | GGSWCiphertext::keyswitch_scratch_space(
+                &module,
+                ct_out.size(),
+                ct_in.size(),
+                ksk.size(),
+                tsk.size(),
+                rank,
+            ),
+    );
+
+    let mut sk_in: SecretKey<Vec<u8>> = SecretKey::new(&module, rank);
+    sk_in.fill_ternary_prob(0.5, &mut source_xs);
+
+    let mut sk_in_dft: SecretKeyFourier<Vec<u8>, FFT64> = SecretKeyFourier::new(&module, rank);
+    sk_in_dft.dft(&module, &sk_in);
+
+    let mut sk_out: SecretKey<Vec<u8>> = SecretKey::new(&module, rank);
+    sk_out.fill_ternary_prob(0.5, &mut source_xs);
+
+    let mut sk_out_dft: SecretKeyFourier<Vec<u8>, FFT64> = SecretKeyFourier::new(&module, rank);
+    sk_out_dft.dft(&module, &sk_out);
+
+    ksk.encrypt_sk(
+        &module,
+        &sk_in,
+        &sk_out_dft,
+        &mut source_xa,
+        &mut source_xe,
+        sigma,
+        scratch.borrow(),
+    );
+    tsk.encrypt_sk(
+        &module,
+        &sk_out_dft,
+        &mut source_xa,
+        &mut source_xe,
+        sigma,
+        scratch.borrow(),
+    );
+
+    pt_scalar.fill_ternary_hw(0, module.n(), &mut source_xs);
+
+    ct_in.encrypt_sk(
+        &module,
+        &pt_scalar,
+        &sk_in_dft,
+        &mut source_xa,
+        &mut source_xe,
+        sigma,
+        scratch.borrow(),
+    );
+
+    ct_out.keyswitch(&module, &ct_in, &ksk, &tsk, scratch.borrow());
+
+    let mut ct_glwe_fourier: GLWECiphertextFourier<Vec<u8>, FFT64> = GLWECiphertextFourier::new(&module, basek, k, rank);
+    let mut pt_dft: VecZnxDft<Vec<u8>, FFT64> = module.new_vec_znx_dft(1, ct_out.size());
+    let mut pt_big: VecZnxBig<Vec<u8>, FFT64> = module.new_vec_znx_big(1, ct_out.size());
+
+    (0..ct_out.rank() + 1).for_each(|col_j| {
+        (0..ct_out.rows()).for_each(|row_i| {
+            module.vec_znx_add_scalar_inplace(&mut pt_want, 0, row_i, &pt_scalar, 0);
+
+            // mul with sk[col_j-1]
+            if col_j > 0 {
+                module.vec_znx_dft(&mut pt_dft, 0, &pt_want, 0);
+                module.svp_apply_inplace(&mut pt_dft, 0, &sk_out_dft, col_j - 1);
+                module.vec_znx_idft_tmp_a(&mut pt_big, 0, &mut pt_dft, 0);
+                module.vec_znx_big_normalize(basek, &mut pt_want, 0, &pt_big, 0, scratch.borrow());
+            }
+
+            ct_out.get_row(&module, row_i, col_j, &mut ct_glwe_fourier);
+
+            ct_glwe_fourier.decrypt(&module, &mut pt_have, &sk_out_dft, scratch.borrow());
+
+            module.vec_znx_sub_ab_inplace(&mut pt_have, 0, &pt_want, 0);
+
+            let noise_have: f64 = pt_have.data.std(0, basek).log2();
+            let noise_want: f64 = noise_gglwe_product(
+                module.n() as f64,
+                basek,
+                0.5,
+                0.5,
+                0f64,
+                sigma * sigma,
+                0f64,
+                rank as f64,
+                k,
+                k,
+            );
+
+            println!("{} {}", noise_have, noise_want);
+
+            // assert!(
+            // (noise_have - noise_want).abs() <= 0.1,
+            // "{} {}",
+            // noise_have,
+            // noise_want
+            // );
+
+            pt_want.data.zero();
+        });
+    });
+}
+
 // fn test_automorphism(p: i64, log_n: usize, basek: usize, k: usize, rank: usize, sigma: f64) {
 // let module: Module<FFT64> = Module::<FFT64>::new(1 << log_n);
 // let rows: usize = (k_ggsw + basek - 1) / basek;