It was little bit guessy challenge i think. So there is no **kks{.\*}**. Then maybe **flag{.\*}** ? why not.
So i tried
> >>> chr(0x02 ^ ord('f'))
> 'd'
> >>> chr(0x09 ^ ord('l'))
> 'e'
> >>> chr(0x00 ^ ord('a'))
> 'a'
> >>> chr(0x03 ^ ord('g'))
> 'd'
> >>> chr(0x19 ^ ord('{'))
> 'b'

*deadb.* ?. Maybe now you guys can guess deadbeer, deadbeef ? is it familiar to you ? anyway if we try **deadbeef** for password. We get a flag

Your flag is: ~~flag{y0u_brute_me}~~ . Okay so right solution is brute-force one. Anyway thanks for reading. If you enjoy subscribe my youtube channel.