added lab2 q1

IS/Lab/Lab1/q6_affine_bf.py

@@ -2,21 +2,16 @@ def main():
     # Affine cipher: E(x) = (ax + b) mod 26
     # Given: "ab" -> "GL"
     # a=0, b=1 -> G=6, L=11
-    # So: 6 = (a*0 + b) mod 26 -> b = 6
-    # And: 11 = (a*1 + b) mod 26 -> 11 = (a + 6) mod 26 -> a = 5
 
     ciphertext = "XPALASXYFGFUKPXUSOGEUTKCDGEXANMGNVS"
 
-    # Try all possible values of a and b for affine cipher
     for a in range(1, 26):
-        # a must be coprime to 26
         if gcd(a, 26) != 1:
             continue
 
         for b in range(26):
-            # Check if this key produces "ab" -> "GL"
+            # if key produces "ab" -> "GL"
             if (a * 0 + b) % 26 == 6 and (a * 1 + b) % 26 == 11:
-                # Found the key, now decrypt the message
                 a_inv = mod_inverse(a, 26)
                 decrypted = ""
                 for char in ciphertext: