We show how to construct a public-key cryptosystem (as originally deened by Diie and Hellman) secure against chosen ciphertext attacks, given a public-key cryptosystem secure against passive eavesdropping and a non-interactive zero-knowledge proof system in the shared string model. No such secure cryptosystems were known before.

Chebyshev polynomials have been recently proposed for designing public-key systems. Indeed, they enjoy some nice chaotic properties, which seem to be suitable for use in Cryptography. Moreover, they satisfy a semi-group property, which makes possible implementing a trapdoor mechanism. In this paper we study a public key cryptosystem based on such polynomials, which provides both encryption and ...

We propose a new homomorphic public-key cryptosystem over arbitrary nonidentity nite group based on the di culty of the membership problem for groups of integer matrices. Besides, a homomorphic cryptosystem is designed for the rst time over nite commutative rings.

In this paper we propose an efficient multivariate public key cryptosystem. Public key of our cryptosystem contains polynomials of total degree three in plaintext and ciphertext variables, two in plaintext variables and one in ciphertext variables. However, it is possible to reduce the public key size by writing it as two sets of quadratic multivariate polynomials. The complexity of encryption ...

We propose the use of reversible cellular automata (RCA) as eecient encryp-tion and decryption devices. The eeciency is due to their inherent parallelism. They can be used both as classical secret-key cryptosystems and as public-key systems.

First implementations of Quantum-key Distribution Cryptosystems have shown the need to use a storage device on which to keep a copy of the key that such cryptosystems create and distribute between a pair of users. Such users must be able to access their device to take enough key to code and decode the messages they send each other over a public channel. Because of the importance of the key stor...

Since the introduction of public-key cryptography by Diffie and Hellman in 1976, the potential for the use of the discrete logarithm problem in public-key cryptosystems has been recognized. Although the discrete logarithm problem as first employed by Diffie and Hellman was defined explicitly as the problem of finding logarithms with respect to a generator in the multiplicative group of the inte...

A new digital signature scheme and public key cryptosystem are proposed which use operations in a prime order subgroup of Z n for a composite number n. There are similarities with the best known digital signatures and public key cryptosystems (RSA and discrete logarithm based schemes) in terms of the mathematical structure. With regard to computational requirements the new schemes are competiti...

At the CRYPTO 2000 conference the seminal KLCHKP (Ko-Lee-CheonHan-Kang-Park) braid group public-key cryptosystem was published see [2]. An updated version of the KLCHKP cryptosystem which is the CKLHC (ChaKo-Lee-Han-Cheon) braid group cryptosystem was introduced at ASIACRYPT 2001 conference [10] the claim of the authors was the updated cryptosystem is based on the DH-DP (Diffie-Hellman Decompos...