2009-02-26

BUBLic's Security^-1

[difficulty: 4] [protection: MD5, NTRU crypto]

MD5 is used on the username to generate what's called a truncated polynomial within the NTRU cryptosystem. It represents the plaintext. The entered serial number encodes a polynomial that is the ciphertext, and the crackme decrypts it to compare it to the plaintext. Keygenning is just enciphering the the poly produced from the username, but a small shortcut can be taken.

No comments:

Post a Comment

thanks for commenting!