Use "calc.exe" in Scientific mode. Select Hex as numeration base then XOR 9f with c7. => 58 which converted to ASCII = 'X' Python: a = 0x9f b = 0xc7 print chr(a^b) => X I don't know if i missed something here, But I used the same method 'calc.exe' I got 58 but in ascii 58 = : so i tried :...