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A5/1 is the strong version of the encryption algorithm used by about 130 million GSM customers in Europe to protect the over-the-air privacy of their cellular voice and data communication. The best published attacks against it require between 2 40 and 2 45 steps. This level of security makes it vulnerable to hardware-based attacks by large organizations,(More)
In 1980 Hellman introduced a general technique for breaking arbitrary block ciphers with N possible keys in time T and memory M related by the tradeoff curve T M 2 = N 2 for 1 ≤ T ≤ N. Recently, Babbage and Golic pointed out that a different T M = N tradeoff attack for 1 ≤ T ≤ D is applicable to stream ciphers, where D is the amount of output data available(More)
Recently a powerful cryptanalytic tool—the slide attack— was introduced [3]. Slide attacks are very successful in breaking iterative ciphers with a high degree of self-similarity and even more surprisingly are independent of the number of rounds of a cipher. In this paper we extend the applicability of slide attacks to a larger class of ciphers. We find(More)
Trivium is a stream cipher designed in 2005 by C. DeCannì ere and B. Preneel for the European project eSTREAM. It has successfully passed the first phase of the project and has been selected for a special focus in the second phase for the hardware portfolio of the project. Trivium has an internal state of size 288 bits and the key of length 80 bits.(More)
Tor is the most popular volunteer-based anonymity network consisting of over 3000 volunteer-operated relays. Apart from making connections to servers hard to trace to their origin it can also provide receiver privacy for Internet services through a feature called "hidden services". In this paper we expose flaws both in the design and implementation of Tor's(More)
In this paper we present two related-key attacks on the full AES. For AES-256 we show the first key recovery attack that works for all the keys and has complexity 2 119 , while the recent attack by Biryukov-Khovratovich-Nikoli´c works for a weak key class and has higher complexity. The second attack is the first cryptanalysis of the full AES-192. Both our(More)
It is a general belief among the designers of block-ciphers that even a relatively weak cipher may become very strong if its number of rounds is made very large. In this paper we describe a new generic known-(or sometimes chosen-) plaintext attack on product ciphers, which we call the slide attack and which in many cases is independent of the number of(More)
HMAC is a widely used message authentication code and a pseudorandom function generator based on cryptographic hash functions such as MD5 and SHA-1. It has been standardized by ANSI, IETF, ISO and NIST. HMAC is proved to be secure as long as the compression function of the underlying hash function is a pseudorandom function. In this paper we devise two new(More)