From ec4253bb1cb056e674f8e35d9916a352a9e34a6c Mon Sep 17 00:00:00 2001
From: Jean-Philippe Bossuat <jeanphilippe.bossuat@gmail.com>
Date: Thu, 12 Jun 2025 11:03:54 +0200
Subject: [PATCH] Added LWESecret

---
 backend/src/scalar_znx.rs          | 20 +++++-----
 core/src/blind_rotation/key.rs     |  4 +-
 core/src/{glwe_keys.rs => keys.rs} | 60 ++++++++++++++++++++++++++++++
 core/src/lib.rs                    |  4 +-
 4 files changed, 74 insertions(+), 14 deletions(-)
 rename core/src/{glwe_keys.rs => keys.rs} (76%)

diff --git a/backend/src/scalar_znx.rs b/backend/src/scalar_znx.rs
index e252a9b..09e7292 100644
--- a/backend/src/scalar_znx.rs
+++ b/backend/src/scalar_znx.rs
@@ -104,12 +104,12 @@ impl<D: AsMut<[u8]> + AsRef<[u8]>> ScalarZnx<D> {
 }
 
 impl<D: From<Vec<u8>>> ScalarZnx<D> {
-    pub(crate) fn bytes_of<S: Sized>(n: usize, cols: usize) -> usize {
-        n * cols * size_of::<S>()
+    pub(crate) fn bytes_of(n: usize, cols: usize) -> usize {
+        n * cols * size_of::<i64>()
     }
 
-    pub(crate) fn new<S: Sized>(n: usize, cols: usize) -> Self {
-        let data = alloc_aligned::<u8>(Self::bytes_of::<S>(n, cols));
+    pub fn new(n: usize, cols: usize) -> Self {
+        let data = alloc_aligned::<u8>(Self::bytes_of(n, cols));
         Self {
             data: data.into(),
             n,
@@ -117,9 +117,9 @@ impl<D: From<Vec<u8>>> ScalarZnx<D> {
         }
     }
 
-    pub(crate) fn new_from_bytes<S: Sized>(n: usize, cols: usize, bytes: impl Into<Vec<u8>>) -> Self {
+    pub(crate) fn new_from_bytes(n: usize, cols: usize, bytes: impl Into<Vec<u8>>) -> Self {
         let data: Vec<u8> = bytes.into();
-        assert!(data.len() == Self::bytes_of::<S>(n, cols));
+        assert!(data.len() == Self::bytes_of(n, cols));
         Self {
             data: data.into(),
             n,
@@ -131,7 +131,7 @@ impl<D: From<Vec<u8>>> ScalarZnx<D> {
 pub type ScalarZnxOwned = ScalarZnx<Vec<u8>>;
 
 pub(crate) fn bytes_of_scalar_znx<B: Backend>(module: &Module<B>, cols: usize) -> usize {
-    ScalarZnxOwned::bytes_of::<i64>(module.n(), cols)
+    ScalarZnxOwned::bytes_of(module.n(), cols)
 }
 
 pub trait ScalarZnxAlloc {
@@ -142,13 +142,13 @@ pub trait ScalarZnxAlloc {
 
 impl<B: Backend> ScalarZnxAlloc for Module<B> {
     fn bytes_of_scalar_znx(&self, cols: usize) -> usize {
-        ScalarZnxOwned::bytes_of::<i64>(self.n(), cols)
+        ScalarZnxOwned::bytes_of(self.n(), cols)
     }
     fn new_scalar_znx(&self, cols: usize) -> ScalarZnxOwned {
-        ScalarZnxOwned::new::<i64>(self.n(), cols)
+        ScalarZnxOwned::new(self.n(), cols)
     }
     fn new_scalar_znx_from_bytes(&self, cols: usize, bytes: Vec<u8>) -> ScalarZnxOwned {
-        ScalarZnxOwned::new_from_bytes::<i64>(self.n(), cols, bytes)
+        ScalarZnxOwned::new_from_bytes(self.n(), cols, bytes)
     }
 }
 
diff --git a/core/src/blind_rotation/key.rs b/core/src/blind_rotation/key.rs
index 4076e14..b4c5d40 100644
--- a/core/src/blind_rotation/key.rs
+++ b/core/src/blind_rotation/key.rs
@@ -1,7 +1,7 @@
 use backend::{Backend, FFT64, Module, ScalarZnx, ScalarZnxAlloc, ScalarZnxToRef, Scratch, ZnxView, ZnxViewMut};
 use sampling::source::Source;
 
-use crate::{AutomorphismKey, GGSWCiphertext, GLWESecret, SecretDistribution};
+use crate::{AutomorphismKey, GGSWCiphertext, GLWESecret, LWESecret, SecretDistribution};
 
 pub struct BlindRotationKeyCGGI<B: Backend> {
     pub(crate) data: Vec<GGSWCiphertext<Vec<u8>, B>>,
@@ -27,7 +27,7 @@ impl BlindRotationKeyCGGI<FFT64> {
         &mut self,
         module: &Module<FFT64>,
         sk_glwe: &GLWESecret<DataSkGLWE, FFT64>,
-        sk_lwe: &GLWESecret<DataSkLWE, FFT64>,
+        sk_lwe: &LWESecret<DataSkLWE>,
         source_xa: &mut Source,
         source_xe: &mut Source,
         sigma: f64,
diff --git a/core/src/glwe_keys.rs b/core/src/keys.rs
similarity index 76%
rename from core/src/glwe_keys.rs
rename to core/src/keys.rs
index be8aa43..9549f15 100644
--- a/core/src/glwe_keys.rs
+++ b/core/src/keys.rs
@@ -17,6 +17,66 @@ pub(crate) enum SecretDistribution {
     NONE,                // Unitialized
 }
 
+pub struct LWESecret<T> {
+    pub(crate) data: ScalarZnx<T>,
+    pub(crate) dist: SecretDistribution,
+}
+
+impl LWESecret<Vec<u8>> {
+    pub fn alloc(n: usize) -> Self {
+        Self {
+            data: ScalarZnx::new(n, 1),
+            dist: SecretDistribution::NONE,
+        }
+    }
+}
+
+impl<DataSelf> LWESecret<DataSelf> {
+    pub fn n(&self) -> usize {
+        self.data.n()
+    }
+
+    pub fn log_n(&self) -> usize {
+        self.data.log_n()
+    }
+
+    pub fn rank(&self) -> usize {
+        self.data.cols()
+    }
+}
+
+impl<D: AsRef<[u8]> + AsMut<[u8]>> LWESecret<D> {
+    pub fn fill_ternary_prob(&mut self, prob: f64, source: &mut Source) {
+        self.data.fill_ternary_prob(0, prob, source);
+        self.dist = SecretDistribution::TernaryProb(prob);
+    }
+
+    pub fn fill_ternary_hw(&mut self, hw: usize, source: &mut Source) {
+        self.data.fill_ternary_hw(0, hw, source);
+        self.dist = SecretDistribution::TernaryFixed(hw);
+    }
+
+    pub fn fill_binary_prob(&mut self, prob: f64, source: &mut Source) {
+        self.data.fill_binary_prob(0, prob, source);
+        self.dist = SecretDistribution::BinaryProb(prob);
+    }
+
+    pub fn fill_binary_hw(&mut self, hw: usize, source: &mut Source) {
+        self.data.fill_binary_hw(0, hw, source);
+        self.dist = SecretDistribution::BinaryFixed(hw);
+    }
+
+    pub fn fill_binary_block(&mut self, block_size: usize, source: &mut Source) {
+        self.data.fill_binary_block(0, block_size, source);
+        self.dist = SecretDistribution::BinaryBlock(block_size);
+    }
+
+    pub fn fill_zero(&mut self) {
+        self.data.zero();
+        self.dist = SecretDistribution::ZERO;
+    }
+}
+
 pub struct GLWESecret<T, B: Backend> {
     pub(crate) data: ScalarZnx<T>,
     pub(crate) data_fourier: ScalarZnxDft<T, B>,
diff --git a/core/src/lib.rs b/core/src/lib.rs
index 3aa05ea..1bffc5a 100644
--- a/core/src/lib.rs
+++ b/core/src/lib.rs
@@ -5,10 +5,10 @@ pub mod gglwe_ciphertext;
 pub mod ggsw_ciphertext;
 pub mod glwe_ciphertext;
 pub mod glwe_ciphertext_fourier;
-pub mod glwe_keys;
 pub mod glwe_ops;
 pub mod glwe_packing;
 pub mod glwe_plaintext;
+pub mod keys;
 pub mod keyswitch_key;
 pub mod tensor_key;
 #[cfg(test)]
@@ -24,10 +24,10 @@ pub use gglwe_ciphertext::*;
 pub use ggsw_ciphertext::*;
 pub use glwe_ciphertext::*;
 pub use glwe_ciphertext_fourier::*;
-pub use glwe_keys::*;
 pub use glwe_ops::*;
 pub use glwe_packing::*;
 pub use glwe_plaintext::*;
+pub use keys::*;
 pub use keyswitch_key::*;
 pub use tensor_key::*;