Merge pull request #24 from serengil/feat-task-2905-bug-in-3072-bit-keys

Feat task 2905 bug in 3072 bit keys

.github/workflows/tests.yml

@@ -57,7 +57,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install pylint
+        pip install pylint==3.0.2
         pip install black
         pip install .
         

lightphe/cryptosystems/ElGamal.py

@@ -1,7 +1,12 @@
+# built-in dependencies
 import random
-import math
+import decimal
 from typing import Optional
+
+# 3rd party dependencies
 import sympy
+
+# project dependencies
 from lightphe.models.Homomorphic import Homomorphic
 from lightphe.commons.logger import Logger
 
@@ -45,7 +50,8 @@ def generate_keys(self, key_size: int):
         p = sympy.randprime(100, 2 ** int(key_size / 2) - 1)
 
         # picking a generator g
-        g = random.randint(2, int(math.sqrt(p)))
+        # g = random.randint(2, int(math.sqrt(p))) # reaches int limit for 3072-bit key
+        g = int(random.uniform(2, float(decimal.Decimal(p).sqrt())))
 
         # picking a private key x
         x = random.randint(1, p - 2)

lightphe/cryptosystems/GoldwasserMicali.py

@@ -128,7 +128,12 @@ def decrypt(self, ciphertext: list) -> int:
             xp = i % p
             xq = i % q
 
-            if pow(xp, int((p - 1) / 2), p) == 1 and pow(xq, int((q - 1) / 2), q) == 1:
+            # reaches int limit for 3072-bit key
+            # if pow(xp, int((p - 1) / 2), p) == 1 and pow(xq, int((q - 1) / 2), q) == 1:
+            if (
+                pow(xp, int((p - 1) // 2), p) == 1
+                and pow(xq, int((q - 1) // 2), q) == 1
+            ):
                 m_binaries.append("0")
             else:
                 m_binaries.append("1")