from pwn import xor with open("./encrypted_data.txt", "r") as f: data = f.readline() key = bytes.fromhex("524A4A3344534350") print(len(key)) dec_key = [] for s in key: s -= 17 if s < ord('A'): s += 26 dec_key.append(s) dec_key[3] = b"3"[0] print("".join(chr(c) for c in dec_key)) data = bytes.fromhex(data) print(xor(data, dec_key))