On the Security of IV Dependent Stream Ciphers

CryptMT v3 is a stream cipher submitted to eStream project, and has entered the third evaluation phase. Any attack has not been found until now. In this paper, we mainly discuss the security of the state initialization process of CryptMT v3. For the key and IV setup function fK , we can construct a probabilistic testing algorithm AfK with a distinguishing probability 1, which indicates that for each key K, fK is a non-PRF. However, we have not found any non-randomness about the keystream output. Key Words. stream cipher, IV setup, CryptMT v3, PRF, PRNG.

• Type: Conference
• Year: 2007
• Where: FSE
• Authors: Côme Berbain, Henri Gilbert
• Keywords: CryptMT V3, Cryptography, FSE 2007, IV Setup, Stream Cipher