Add parallel implementation

ChaCha20_Poly1305_64/sim/do_poly_1305.py

@@ -36,8 +36,33 @@ def poly1305(message: bytes, r: int, s: int):
 
     return acc & (2**128-1)
 
+def parallel_poly1305(message: bytes, r: int, s: int, lanes: int):
+    r = mask_r(r)
+    p = 2**130-5
     
-def main():
+    acc = [0]*lanes
+
+    blocks = [int.from_bytes(message[i:i+16], "little") for i in range(0, len(message), 16)]
+
+    lane_blocks = [blocks[i:i+lanes] for i in range(0, len(blocks), lanes)]
+
+    for i, lane_block in enumerate(lane_blocks):
+        for j, lane in enumerate(lane_block):
+            idx = i*lanes + j
+            power = min(lanes, len(blocks) - idx)
+
+            byte_length = (lane.bit_length() + 7) // 8
+            lane += 1 << (8*byte_length)
+
+            acc[j] = ((acc[j] + lane)*(r**power)) % p
+
+    combined_acc = sum(acc) % p
+    combined_acc += s
+
+    return combined_acc & (2**128-1)
+
+
+def test_regular():
     r = 0xa806d542fe52447f336d555778bed685
     s = 0x1bf54941aff6bf4afdb20dfb8a800301
     
@@ -50,5 +75,37 @@ def main():
     print(f"{golden_result:x}")
     print(f"{result:x}")
 
+def test_parallel():
+    r = 0xa806d542fe52447f336d555778bed685
+    s = 0x1bf54941aff6bf4afdb20dfb8a800301
+    
+    golden_result = 0xa927010caf8b2bc2c6365130c11d06a8
+
+    msg = b"Cryptographic Forum Research Group"
+
+    result = parallel_poly1305(msg, r, s, 8)
+    
+    print(f"{golden_result:x}")
+    print(f"{result:x}")
+
+
+def test_on_long_string():
+    r = 0xa806d542fe52447f336d555778bed685
+    s = 0x1bf54941aff6bf4afdb20dfb8a800301
+
+    msg = b"Very long message with lots of words that is very long and requires a lot of cycles to complete because of how long it is"
+
+    regular_result = poly1305(msg, r, s)
+    parallel_result = parallel_poly1305(msg, r, s, 8)
+
+    print(f"{regular_result:x}")
+    print(f"{parallel_result:x}")
+
+
+def main():
+    test_regular()
+    test_parallel()
+    test_on_long_string()
+
 if __name__ == "__main__":
     main()