Merge pull request #353 from fboemer/fboemer/faster-ckks-square

Optimize CKKS square
microsoft · Jun 15, 2021 · 16f40b4 · 16f40b4
2 parents a865133 + e1b0ed2
commit 16f40b4
Showing 1 changed file with 7 additions and 12 deletions.
diff --git a/native/src/seal/evaluator.cpp b/native/src/seal/evaluator.cpp
@@ -847,21 +847,16 @@ namespace seal
         // Set up iterators for input ciphertext
         auto encrypted_iter = iter(encrypted);
 
-        // Allocate temporary space for the result
-        SEAL_ALLOCATE_ZERO_GET_POLY_ITER(temp, dest_size, coeff_count, coeff_modulus_size, pool);
-
-        // Compute c0^2
-        dyadic_product_coeffmod(encrypted_iter[0], encrypted_iter[0], coeff_modulus_size, coeff_modulus, temp[0]);
+        // Compute c1^2
+        dyadic_product_coeffmod(
+            encrypted_iter[1], encrypted_iter[1], coeff_modulus_size, coeff_modulus, encrypted_iter[2]);
 
         // Compute 2*c0*c1
-        dyadic_product_coeffmod(encrypted_iter[0], encrypted_iter[1], coeff_modulus_size, coeff_modulus, temp[1]);
-        add_poly_coeffmod(temp[1], temp[1], coeff_modulus_size, coeff_modulus, temp[1]);
+        dyadic_product_coeffmod(encrypted_iter[0], encrypted_iter[1], coeff_modulus_size, coeff_modulus, encrypted_iter[1]);
+        add_poly_coeffmod(encrypted_iter[1], encrypted_iter[1], coeff_modulus_size, coeff_modulus, encrypted_iter[1]);
 
-        // Compute c1^2
-        dyadic_product_coeffmod(encrypted_iter[1], encrypted_iter[1], coeff_modulus_size, coeff_modulus, temp[2]);
-
-        // Set the final result
-        set_poly_array(temp, dest_size, coeff_count, coeff_modulus_size, encrypted.data());
+       // Compute c0^2
+        dyadic_product_coeffmod(encrypted_iter[0], encrypted_iter[0], coeff_modulus_size, coeff_modulus, encrypted_iter[0]);
 
         // Set the scale
         encrypted.scale() = new_scale;