Showing papers on "Round function published in 2001"
09 Dec 2001
TL;DR: This work examines the pseudorandomness of the block cipher KASUMI and the provable security of f8 and shows that the three round KASumI is not a Pseudo-Pseudorandom permutation ensemble but the four round KasUMI is a pseud orandom permutations ensemble under the adaptive distinguisher model.
Abstract: Within the security architecture of the 3GPP system there is a standardised encryption mode f8 based on the block cipher KASUMI. In this work we examine the pseudorandomness of the block cipher KASUMI and the provable security of f8. First we show that the three round KASUMI is not a pseudorandom permutation ensemble but the four round KASUMI is a pseudorandom permutation ensemble under the adaptive distinguisher model by investigating the properties of the round functions in a clear way. Second we provide the upper bound on the security of f8 mode under the reasonable assumption from the first result by means of the left-or-right security notion.
34 citations
Patent•
25 Oct 2001TL;DR: In this article, the round function of the Data Encryption Standard (DES) was implemented on general-purpose, embedded, and cryptographic processors, and the transformations associated with the expansion permutation from DES round function to the DES round key computation function were performed.
Abstract: An efficient software implementation of the round function of the Data Encryption Standard (DES) involves mathematical transformations performed on the DES round function and the DES round key computation function that reduce the computation required to complete a DES round on general-purpose, embedded, and cryptographic processors. These transformations shift computation associated with the Expansion Permutation from the DES round function to the DES round key computation function. As a result, fewer instructions are required to compute the inputs of the DES S-boxes in the round function.
12 citations
02 Apr 2001
TL;DR: This paper proves that the five round MISTY type structure is super-pseudorandom, and characterize its round security.
Abstract: The security of an iterated block cipher heavily depends on its structure as well as each round function. Matsui showed that MISTY type structure is faster and more robust than Feistel structure on linear cryptanalysis and differential cryptanalysis. On the other hand, Luby and Rackoff proved that the four round Feistel structure is superpseudorandom if each round function fi is a random function. This paper proves that the five round MISTY type structure is super-pseudorandom. We also characterize its round security.
11 citations