Suche ›

Advances in Cryptology

Proceedings of CRYPTO '84

Springer Berlin,
50,28 € Lieferbar in 2-3 Tagen


A Workshop on the Theory and Application of Cryptographic Techniques. Held at the University of California, Santa Barbara, August 19 - 22, 1984


Titel: Advances in Cryptology
Autoren/Herausgeber: G.R. Blakely, D. Chaum (Hrsg.)
Aus der Reihe: Lecture Notes in Computer Science
Ausgabe: 1985

ISBN/EAN: 9783540156581

Seitenzahl: 496
Format: 23,5 x 15,5 cm
Produktform: Taschenbuch/Softcover
Gewicht: 1,560 g
Sprache: Englisch

Recently, there has been a lot of interest in provably "good" pseudo-random number generators [lo, 4, 14, 31. These cryptographically secure generators are "good" in the sense that they pass all probabilistic polynomial time statistical tests. However, despite these nice properties, the secure generators known so far suffer from the han- cap of being inefiicient; the most efiicient of these take n2 steps (one modular multip- cation, n being the length of the seed) to generate one bit. Pseudc-random number g- erators that are currently used in practice output n bits per multiplication (n2 steps). An important open problem was to output even two bits on each multiplication in a cryptographically secure way. This problem was stated by Blum, Blum & Shub [3] in the context of their z2 mod N generator. They further ask: how many bits can be o- put per multiplication, maintaining cryptographic security? In this paper we state a simple condition, the XOR-Condition and show that any generator satisfying this condition can output logn bits on each multiplication. We show that the XOR-Condition is satisfied by the lop least significant bits of the z2-mod N generator. The security of the z2 mod N generator was based on Quadratic Residu- ity [3]. This generator is an example of a Trapdoor Generator [13], and its trapdoor properties have been used in protocol design. We strengthen the security of this gene- tor by proving it as hard as factoring. - Newsletter
Möchten Sie sich für den Newsletter anmelden?

Bitte geben Sie eine gültige E-Mail-Adresse ein.
Lieber nicht