updated repo for publishing (#74)

poulpy-core/src/conversion/glwe_to_lwe.rs

@@ -0,0 +1,80 @@
+use poulpy_backend::hal::{
+    api::{
+        ScratchAvailable, TakeVecZnxDft, VecZnxBigAddSmallInplace, VecZnxBigNormalize, VecZnxBigNormalizeTmpBytes,
+        VecZnxDftAllocBytes, VecZnxDftFromVecZnx, VecZnxDftToVecZnxBigConsume, VmpApply, VmpApplyAdd, VmpApplyTmpBytes, ZnxView,
+        ZnxViewMut, ZnxZero,
+    },
+    layouts::{Backend, DataMut, DataRef, Module, Scratch},
+};
+
+use crate::{
+    TakeGLWECt,
+    layouts::{GLWECiphertext, Infos, LWECiphertext, prepared::GLWEToLWESwitchingKeyPrepared},
+};
+
+impl LWECiphertext<Vec<u8>> {
+    pub fn from_glwe_scratch_space<B: Backend>(
+        module: &Module<B>,
+        n: usize,
+        basek: usize,
+        k_lwe: usize,
+        k_glwe: usize,
+        k_ksk: usize,
+        rank: usize,
+    ) -> usize
+    where
+        Module<B>: VecZnxDftAllocBytes + VmpApplyTmpBytes + VecZnxBigNormalizeTmpBytes,
+    {
+        GLWECiphertext::bytes_of(n, basek, k_lwe, 1)
+            + GLWECiphertext::keyswitch_scratch_space(module, n, basek, k_lwe, k_glwe, k_ksk, 1, rank, 1)
+    }
+}
+
+impl<DLwe: DataMut> LWECiphertext<DLwe> {
+    pub fn sample_extract<DGlwe: DataRef>(&mut self, a: &GLWECiphertext<DGlwe>) {
+        #[cfg(debug_assertions)]
+        {
+            assert!(self.n() <= a.n());
+        }
+
+        let min_size: usize = self.size().min(a.size());
+        let n: usize = self.n();
+
+        self.data.zero();
+        (0..min_size).for_each(|i| {
+            let data_lwe: &mut [i64] = self.data.at_mut(0, i);
+            data_lwe[0] = a.data.at(0, i)[0];
+            data_lwe[1..].copy_from_slice(&a.data.at(1, i)[..n]);
+        });
+    }
+
+    pub fn from_glwe<DGlwe, DKs, B: Backend>(
+        &mut self,
+        module: &Module<B>,
+        a: &GLWECiphertext<DGlwe>,
+        ks: &GLWEToLWESwitchingKeyPrepared<DKs, B>,
+        scratch: &mut Scratch<B>,
+    ) where
+        DGlwe: DataRef,
+        DKs: DataRef,
+        Module<B>: VecZnxDftAllocBytes
+            + VmpApplyTmpBytes
+            + VecZnxBigNormalizeTmpBytes
+            + VmpApply<B>
+            + VmpApplyAdd<B>
+            + VecZnxDftFromVecZnx<B>
+            + VecZnxDftToVecZnxBigConsume<B>
+            + VecZnxBigAddSmallInplace<B>
+            + VecZnxBigNormalize<B>,
+        Scratch<B>: ScratchAvailable + TakeVecZnxDft<B> + TakeGLWECt,
+    {
+        #[cfg(debug_assertions)]
+        {
+            assert_eq!(self.basek(), a.basek());
+            assert_eq!(a.n(), ks.n());
+        }
+        let (mut tmp_glwe, scratch1) = scratch.take_glwe_ct(a.n(), a.basek(), self.k(), 1);
+        tmp_glwe.keyswitch(module, a, &ks.0, scratch1);
+        self.sample_extract(&tmp_glwe);
+    }
+}