Block cipher challenge

Level: CTR mode

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



Ciphertext (hexencoded), for easy copy-paste

12b1573792ee522482602959906d3b0d52139481dcf233ec9e5825c4de15a3b700ceb9eca91a65cd59526c3265155d42b423e7d2f73253bc9ec81536bbf28623

Ciphertext (hexencoded):

12b1573792ee522482602959906d3b0d 52139481dcf233ec9e5825c4de15a3b7 00ceb9eca91a65cd59526c3265155d42 b423e7d2f73253bc9ec81536bbf28623

Plaintext (hexencoded):

12b1573792ee522482602959906d3b0d 7b22757365726e616d65223a20226775 657374222c202269735f677565737422 3a20747275657d090909090909090909

Plaintext:

\x12\xb1W7\x92\xeeR$\x82`)Y\x90m;\r {"username": "gu est", "is_guest" : true}\t\t\t\t\t\t\t\t\t

Final plaintext

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