The secret mainframe for a distributed hacker group has been discovered. We have managed to exfiltrate some of the code that it runs, but we don’t have a physical copy of their access badges. Can you still get the flag? source Remote: nc 1 Note: enter flag as pbctf{lower_case_flag_text} Looking at the provided source, the cipher procedes in $2\lceil\log_2 |m|\rceil$ rounds to encrypt a message $m$. Each round replaces each bigram through the sbox (which is unknown and the key) $S$, and reorganizes the message such that all bigrams are broken up.