Pisarchik et al. presented an image encryption algorithm based on chaotically coupled chaotic maps. But G. Arroyo et al. found some flaws and security weaknesses in the proposed cryptosystem. In this letter, the speed of this chaotic cryptosystem is analyzed and the encryption speed claimed by the authors is argued. The maximum possible speed for the proposed algorithm is calculated analyticall...

The RSA cryptosystem is supposed to be the first realization of a public key cryptosystem in 1977. Its (computational) security is relied upon the difficulty of factorization. In order to break the RSA cryptosystem it is enough to factorize where is the product of two large prime numbers, . This is equivalent to calculate where is the Euler function. In this paper Neural Networks are trained in...

In this paper, we construct a new threshold cryptosystem from the Gap Diffie-Hellman (GDH) group. The proposed scheme enjoys all the most important properties that a robust and practical threshold cryptosystem should possess, that is, it is noninteractive, computationally efficient and provably secure against adaptive chosen ciphertext attacks. In addition, thanks to the elegant structure of th...

Protecting data and its communication is a critical part of the modern network. The science of protecting data, known as cryptography, uses secret keys to encrypt data in a format that is not easily decipherable. However,most commonly secure logons for a workstation connected to a network use passwords to perform user authentication. These passwords are a weak link in the security chain, and ar...

1053-5888/15©2015IEEE B iometrics were originally developed for identification, such as for criminal investigations. More recently, biometrics have been also utilized for authentication. Most biometric authentication systems today match a user’s biometric reading against a stored reference template generated during enrollment. If the reading and the template are sufficiently close, the authenti...

The main contribution of this thesis is a simplification, a generalization and some modifications of the homomorphic cryptosystem proposed by Paillier in 1999, and several cryptological protocols that follow from these changes. The Paillier cryptosystem is an additive homomorphic cryptosystem, meaning that one can combine ciphertexts into a new ciphertext that is the encryption of the sum of th...

In present world, biometric base authentication system is used by many agencies for security purpose. Use of important characteristics of biometric based authentication system become so popular because every human presents unique biometric characteristics and biometric recognition done automatically. Biometric authentication system is divided into four steps like biometric template acquisition ...

An analysis of a recently proposed cryptosystem based on chaotic oscillators and feedback inversion is presented. It is shown how the cryptosystem can be broken when Duffing’s oscillator is considered. Some implementation problems of the system are also discussed.

We develop a public key cryptosystem based on invariants of diagonalizable groups. Theoretical results about degrees of invariants, which are related to the security of such cryptosystem, are derived. Further, we derive results on invariants of superanalogs of tori.

We present our experience from implementing the public-key cryptosystem of González, Boyd and Dawson. We discuss different computational methods and compare their relative efficiency experimentally. We also compare the efficiency of this cryptosystem with that of the ElGamal cipher.