Slightly refactored compress_q and ran cargo fmt.

cryspen · Oct 11, 2023 · a981c0f · a981c0f
1 parent ef6b8ad
commit a981c0f
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Showing 2 changed files with 2 additions and 6 deletions.
diff --git a/src/kem/kyber/compress.rs b/src/kem/kyber/compress.rs
@@ -7,13 +7,11 @@ use super::{
 fn compress_q<const COEFFICIENT_BITS: usize>(fe: u16) -> KyberFieldElement {
     debug_assert!(COEFFICIENT_BITS <= BITS_PER_COEFFICIENT);
 
-    let two_pow_bit_size = 1u32 << COEFFICIENT_BITS;
-
-    let mut compressed = (fe as u32) * (two_pow_bit_size << 1);
+    let mut compressed = (fe as u32) << (COEFFICIENT_BITS + 1);
     compressed += FIELD_MODULUS as u32;
     compressed /= (FIELD_MODULUS << 1) as u32;
 
-    (compressed & (two_pow_bit_size - 1)) as KyberFieldElement
+    (compressed & ((1u32 << COEFFICIENT_BITS) - 1)) as KyberFieldElement
 }
 pub fn compress<const COEFFICIENT_BITS: usize>(
     mut re: KyberPolynomialRingElement,
@@ -41,4 +39,3 @@ pub fn decompress<const COEFFICIENT_BITS: usize>(
         .map(|coefficient| decompress_q::<COEFFICIENT_BITS>(coefficient));
     re
 }
-
diff --git a/src/kem/kyber/ind_cpa.rs b/src/kem/kyber/ind_cpa.rs
@@ -29,7 +29,6 @@ pub fn serialize_secret_key<const SERIALIZED_KEY_LEN: usize>(
         .array()
 }
 
-
 #[inline(always)]
 #[allow(non_snake_case)]
 fn sample_matrix_A<const K: usize>(