Code organisation for glwe

core/src/glwe/public_key.rs

@@ -0,0 +1,75 @@
+use backend::{Backend, FFT64, Module, ScratchOwned, VecZnxDft};
+use sampling::source::Source;
+
+use crate::{FourierGLWECiphertext, GLWESecret, Infos, keys::SecretDistribution};
+
+pub struct GLWEPublicKey<D, B: Backend> {
+    pub(crate) data: FourierGLWECiphertext<D, B>,
+    pub(crate) dist: SecretDistribution,
+}
+
+impl<B: Backend> GLWEPublicKey<Vec<u8>, B> {
+    pub fn alloc(module: &Module<B>, basek: usize, k: usize, rank: usize) -> Self {
+        Self {
+            data: FourierGLWECiphertext::alloc(module, basek, k, rank),
+            dist: SecretDistribution::NONE,
+        }
+    }
+
+    pub fn bytes_of(module: &Module<B>, basek: usize, k: usize, rank: usize) -> usize {
+        FourierGLWECiphertext::<Vec<u8>, B>::bytes_of(module, basek, k, rank)
+    }
+}
+
+impl<T, B: Backend> Infos for GLWEPublicKey<T, B> {
+    type Inner = VecZnxDft<T, B>;
+
+    fn inner(&self) -> &Self::Inner {
+        &self.data.data
+    }
+
+    fn basek(&self) -> usize {
+        self.data.basek
+    }
+
+    fn k(&self) -> usize {
+        self.data.k
+    }
+}
+
+impl<T, B: Backend> GLWEPublicKey<T, B> {
+    pub fn rank(&self) -> usize {
+        self.cols() - 1
+    }
+}
+
+impl<C: AsRef<[u8]> + AsMut<[u8]>> GLWEPublicKey<C, FFT64> {
+    pub fn generate_from_sk<S: AsRef<[u8]>>(
+        &mut self,
+        module: &Module<FFT64>,
+        sk: &GLWESecret<S, FFT64>,
+        source_xa: &mut Source,
+        source_xe: &mut Source,
+        sigma: f64,
+    ) {
+        #[cfg(debug_assertions)]
+        {
+            match sk.dist {
+                SecretDistribution::NONE => panic!("invalid sk: SecretDistribution::NONE"),
+                _ => {}
+            }
+        }
+
+        // Its ok to allocate scratch space here since pk is usually generated only once.
+        let mut scratch: ScratchOwned = ScratchOwned::new(FourierGLWECiphertext::encrypt_sk_scratch_space(
+            module,
+            self.basek(),
+            self.k(),
+            self.rank(),
+        ));
+
+        self.data
+            .encrypt_zero_sk(module, sk, source_xa, source_xe, sigma, scratch.borrow());
+        self.dist = sk.dist;
+    }
+}