degrees of freedom despite being transmitted in a 184-bit format. Additionally, we find that two or more keystream frames can be derived from a single message in four of the six channels through which this message type may be transmitted. Assuming the CIPHERING MODE COMMAND message type is transmitted using one of these four channels, we can iteratively guess the message and conduct a known plaintext attack to recover the session key. Thanks to the speed improvement achieved by our pre-filtration method, our ciphertext-only attack can recover the session key in 1.3 seconds.">
A Practical Ciphertext-Only Attack on GMR-2 System (original) (raw)