Publication

On the Lai-Massey scheme

Serge Vaudenay
1999
Conference Papers

Abstract

Constructing a block cipher requires us to define a random permutation, which is usually performed by the Feistel scheme and its variants. In this paper we investigate the Lai-Massey scheme which was used in IDEA. We show that we cannot use it Â as isÂ in order to obtain results like the Luby-Rackoff theorem. This can however be done by introducing a simple function which has an orthomorphism property. We also show that this design offers nice decorrelation properties, and we propose a block cipher family called Walnut

Official source

https://infoscience.epfl.ch/entities/publication/11e8e784-5f63-4816-93b7-cb523dfbc4e2

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Serge Vaudenay
1999
Conference Papers

Abstract

Official source

https://infoscience.epfl.ch/entities/publication/11e8e784-5f63-4816-93b7-cb523dfbc4e2

About this result

Related concepts (14)

Block cipher

In cryptography, a block cipher is a deterministic algorithm that operates on fixed-length groups of bits, called blocks. Block ciphers are the elementary building blocks of many cryptographic protocols. They are ubiquitous in the storage and exchange of data, where such data is secured and authenticated via encryption. A block cipher uses blocks as an unvarying transformation. Even a secure block cipher is suitable for the encryption of only a single block of data at a time, using a fixed key.

Feistel cipher

In cryptography, a Feistel cipher (also known as Luby–Rackoff block cipher) is a symmetric structure used in the construction of block ciphers, named after the German-born physicist and cryptographer Horst Feistel, who did pioneering research while working for IBM; it is also commonly known as a Feistel network. A large proportion of block ciphers use the scheme, including the US Data Encryption Standard, the Soviet/Russian GOST and the more recent Blowfish and Twofish ciphers.

Pseudorandom permutation

In cryptography, a pseudorandom permutation (PRP) is a function that cannot be distinguished from a random permutation (that is, a permutation selected at random with uniform probability, from the family of all permutations on the function's domain) with practical effort. Let F be a mapping . F is a PRP if and only if For any , is a bijection from to , where . For any , there is an "efficient" algorithm to evaluate for any ,.

Related publications (1)

On the Lai-Massey scheme

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Decorrelation over infinite domains: the encrypted CBC-MAC case