## Cryptology ePrint Archive: Report 2002/178

Attack on A New Public Key Cryptosystem from ISC'02 (LNCS 2433)

Fangguo Zhang, Shengli Liu and Kwangjo Kim

Abstract: In ISC 2002, J. Zheng 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, the underlying problem of Zheng's public key cryptosystem is not a hard'' problem.

Category / Keywords: Public key cryptography, Attack, Polynomial,Matrix, Finite field