How to construct pseudorandom permutations from pseudorandom functions
SIAM Journal on Computing - Special issue on cryptography
Computing algebraic formulas with a constant number of registers
STOC '88 Proceedings of the twentieth annual ACM symposium on Theory of computing
Bounded-width polynomial-size branching programs recognize exactly those languages in NC1
Journal of Computer and System Sciences - 18th Annual ACM Symposium on Theory of Computing (STOC), May 28-30, 1986
Methodologies for designing block ciphers and cryptographic protocols
Methodologies for designing block ciphers and cryptographic protocols
Differential Cryptanalysis of DES-like Cryptosystems
CRYPTO '90 Proceedings of the 10th Annual International Cryptology Conference on Advances in Cryptology
IBM Journal of Research and Development - Mathematics and computing
Theoretical Computer Science - Automata, languages and programming: Algorithms and complexity (ICALP-A 2004)
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The D.E.S. cipher is naturally viewed as a composition of sixteen invertible transformations on 64-bit strings (where the transformations depend of the value of a 56-bit key). Each of the transformations has a special form and satisfies the particular property that each of its output bits is determined by a "small" number of its input bits. We investigate the computational power of block ciphers on n-bit strings that can be expressed as polynomial-length (with respect to n) compositions of invertible transformations that have a form similar to those of D.E.S. In particular, we require that the basic transformations have the property that each of their output bits depends on the value of a small number of their input bits (where "small" is somewhere in the range between O(1) and O(log n)). We present some sufficient conditions for ciphers of this type to be "pseudorandom function generators" and, thus, to yield private key cryptosystems that are secure against adaptive chosen plaintext attacks.