In Crypto 97, a public key cryptosystem based on the closest vector problem was suggested by Goldreich, Goldwasser and Halevi [4]. In this paper, we propose a public key cryptosystem applying representations of polynomials to the GGH encryption scheme. Its key size is much smaller than the GGH system so that it is a quite practical and efficient lattice based cryptosystem.

In ISC 2002, J. Zheng [8] proposed a new public key cryptosystem whose security is based upon the algebraic problem of reducing a high degree matrix to its canonical form by similarity transformations. In this paper, we show that factoring a polynomial over a finite field can be used to break down Zheng’s public key cryptosystem. The complexity of our attack is polynomial time. In other word, t...

This paper proposes an efficient joint secret key encryption-channel coding cryptosystem, based on regular Extended Difference Family Quasi-Cyclic Low-Density Parity-Check codes. The key length of the proposed cryptosystem decreases up to 85 percent using a new efficient compression algorithm. Cryptanalytic methods show that the improved cryptosystem has a significant security advantage over Ra...

In this paper, for given N = pq with p and q different odd primes, and m = 1, 2, · · · , we give a public key cryptosystem. When m = 1 the system is just the famous RSA system. And when m ≥ 2, the system is usually more secure than the one with m = 1.

We describe a new trap-door (and PKC) proposal. The proposal is “multivariate quadratic” (relies on the hardness of solving systems of quadratic equations); it is also code-based, and uses the code-scrambling technique of McEliece (1978). However, in the new proposal, the errorcorrecting code is not revealed in the public key, which protects against the leading attacks on McEliece’s method.

A public key cryptosystem based on Drinfeld modules has been proposed by Gillard, Leprevost, Panchishkin and Roblot. The paper shows how an adversary can directly recover a private key using only the public key, and so the cryptosystem is insecure.

We show that the plaintext of some of the proposed CCA2 conversions of McEliece cryptosystem with a public key in systematic form can be recovered faster than with a general linear decoding. This is due to the fact that an attacker only needs to recover a part of the cleartext to decrypt the relevant plaintext.

The proposed PKC has two main advantages that will make it applicable to the real world. The first one is a decoding algorithm with an expected runtime of O(n) elementary operations. The second advantage is that the corresponding matrix A is of the form A = [A′ | I], where I is the identity matrix and A′ being completely random, in contrast to e.g. McEliece-Type systems (cf. [1]), which means t...