prove constructively that universal one-way hash functions exist if any 1-1 one-way functions exist. Among the various applications of the primitive is a One-Way based Secure Digital Signature Scheme which is existentially secure against adoptive attacks. Previously, all provably secure signature

similar but weaker result for almost all odd numbers n. We also discuss some cryptographic applications. 1

Abstract. The applications that use cryptography as well as the employed devices pose various requirements and constraints. These have to be considered during the development or analysis of cryptographic algorithms that are secure and practicable. This paper presents several real

in various integer sequences. We then turn our attention to cryptographic applications in which smooth numbers play a pivotal role.

The use of FPGAs for cryptographic applications is highly attractive for a variety of reasons but at the same time there are many open issues related to the general security of FPGAs. This contribution attempts to provide a state-of-the-art description of this topic. First, the advantages

Identification is a useful cryptographic tool. Since the zero-knowledge theory appeared [3], several interactive identification schemes have been proposed (in particular Fiat-Shamir [2] and its variants [4, 6, 5], Schnorr [8]). These identifications are based on number theoretical problems. More

Abstract. Since the development of the RSA cryptographic system by Rivest, Shamir, and Adleman, in 1977, RSA has become a cornerstone of communica-tion security. However, as computers gain in processing speed, it is imperative that stronger cryptographic schemes be implemented in order to withstand

Abstract — This paper analyzes the use of the logistic map for cryptographic applications. The most important characteristics of the logistic map are shown in order to prove the inconvenience of considering this map in the design of new chaotic cryptosystems. I.

and cryptography it has a large variety of applications. Combined with another tool we develop which we call “on-line simulatable NIZK proofsystem”, it is the key tool used to solve the open problem of the existence of a many prover non-interactive zero-knowledge system (MP-NIZK proof system). This problem

A method of generating a practically unlimited number of quasigroups of a (theoretically) arbitrary order using the computer algebra system Maple 7 is presented. This problem is crucial to cryptography and its solution permits to implement practical quasigroup-based endomorphic cryptosystems. The order of a quasigroup usually equals the number of characters of the alphabet used for recording both the plaintext and the ciphertext. From the practical viewpoint, the most important quasigroups are of order 256, suitable for a fast software encryption of messages written down in the universal ASCII code. That is exactly what this paper provides: fast and easy ways of generating quasigroups of order up to 256 and a little more.