Block cipher challenge

Level: CTR mode

Sorry, you're not an admin (need is_admin: true)



Ciphertext (hexencoded), for easy copy-paste

ef9f4a78a7e5396ba29973ae4e635bc7eb5b3947146a21866b46a0b6593ade58b1fea92c04cdd1f10ae30fd4f6246bf49efd4f483d38a38a6b8a401c56456aae

Ciphertext (hexencoded):

ef9f4a78a7e5396ba29973ae4e635bc7 eb5b3947146a21866b46a0b6593ade58 b1fea92c04cdd1f10ae30fd4f6246bf4 9efd4f483d38a38a6b8a401c56456aae

Plaintext (hexencoded):

ef9f4a78a7e5396ba29973ae4e635bc7 7b22757365726e616d65223a20226775 657374222c202269735f677565737422 3a20747275657d090909090909090909

Plaintext:

\xef\x9fJx\xa7\xe59k\xa2\x99s\xaeNc[\xc7 {"username": "gu est", "is_guest" : true}\t\t\t\t\t\t\t\t\t

Final plaintext

{"username": "guest", "is_guest": true}