In this paper we will construct a lattice-based public-key cryptosystem using non-commutative quaternion algebra, and since its lattice does not fully fit within Circular and Convolutional Modular Lattice (CCML), we prove it is arguably more secure than the existing lattice-based cryptosystems such as NTRU. As in NTRU, the proposed public-key cryptosystem relies for its inherent securi...

Key agreement protocols are essential for secure communications in open and distributed environments. Recently, identity-based key agreement protocols have been increasingly researched because of the simplicity of public key management. The basic idea behind an identity-based cryptosystem is that a public key is the identity (an arbitrary string) of a user, and the corresponding private key is ...

The Secure Encryption Technique (SET) is a Private Key Block Cipher Cryptosystem which has been modified on the platform of Triple SV. This cryptosystem inherits its basic architecture and function from TSV and then it has been developed further to provide better security with the ease of use for even the basic requirements of encryption system. The key is a 2 bit (128 bit) key and the encrypti...

In this paper we provide a quantum public-key cryptosystem based on super dense coding technology. A user Alice shares a set of Einstein-Podolsky-Rosen (EPR) pairs with a key management center (KMC) in which the particles hold by Alice are the private key and the particle hold by KMC are the public key. By the help of the key management center any other user can send encrypted message to Alice....

Received Oct 5 th , 2012 Accepted Oct 30 th , 2012 Using more than two factors in the modulus of the RSA cryptosystem has the arithmetic advantage that the private key computation can be speeded up by CRT. With this idea, we present an efficient combination of two variants of RSA cryptosystem (Batch and Mprime RSA) which makes the decryption process faster than the existing variants. It can not...

We propose BQTRU, a non-commutative NTRU-like cryptosystem over quaternion algebras. This cryptosystem uses bivariate polynomials as the underling ring. The multiplication operation in our cryptosystem can be performed with high speed using quaternions algebras over finite rings. As a consequence, the key generation and encryption process of our cryptosystem is faster than NTRU in comparable pa...

We present protocols for threshold cryptography in the GBD public-key cryptosystem. Both threshold decryption and threshold key generation are covered, in the “honest-butcurious” setting. This shows that it is possible to perform GBD computations in a distributed manner during both key generation and decryption, without revealing the private key to any party. GBD threshold decryption is similar...

In this paper we propose a new approach to investigate the security of the McEliece cryptosystem. We recall that this cryptosystem relies on the use of error-correcting codes. Since its invention thirty years ago, no efficient attack had been devised that managed to recover the private key. We prove that the private key of the cryptosystem satisfies a system of bi-homogeneous polynomial equatio...

We present protocols for threshold decryption and threshold key generation in the GBD public-key cryptosystem in the “honest-butcurious” setting. These allow GBD computations to be performed in a distributed manner during both key generation and decryption, without revealing the private key to any party. GBD threshold decryption is similar to El-Gamal threshold decryption. GBD threshold key gen...

In this paper, we proposed a new attack against Hwang et al.’s cryptosystem. This cryptosystem uses a super-increasing sequence as private key and the authors investigate a new algorithm called permutation combination algorithm to enhance density of knapsack to avoid the low-density attack. Sattar J. Aboud [Aboud j. Sattar, “An improved knapsack public key cryptography system”, International Jo...