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Crypto - News

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Crypto - News | Security - News

11 / 2006
Vybrali pro vás: TR - Tomáš Rosa, JP - Jaroslav Pinkava, PV - Pavel Vondruška, VK - Vlastimil Klíma

Vl.Klíma: A New Concept of Hash Functions SNMAC Using a Special Block Cipher and NMAC/HMAC Constructions

06.11.2006
Abstract:
In this paper, we present new security proofs of well-known hash constructions NMAC/HMAC proposed by Bellare et al. in 1996. We introduce a new cryptographic primitive called special block cipher (SBC) which is resistant to attacks specific for block ciphers used in hash functions. We propose to use SBC in the NMAC/HMAC constructions, what gives rise to the new concept of hash functions called Special NMAC (SNMAC). From our new NMAC/HMAC security proofs it follows that SNMAC hash functions are computationally resistant to preimage and collision attacks. Moreover, at CRYPTO 2005 Coron et al. proved that SNMAC is indifferentiable from a random oracle in the limit. SNMAC construction is general and it enables various proposals using different instances of the special block ciphers. We propose a special block cipher DN (Double Net) and define a hash function HDN (Hash Double Net) as the SNMAC construction based on DN.
Zdroj: http://eprint.iacr.org/2006/376.pdf
Autor: JP


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