Paper 2009/208

PUBLIC KEY CRYPTOGRAPHY USING PERMUTATION P-POLYNOMIALS OVER FINITE FIELDS

Rajesh P Singh and B.K.Sarma and A.Saikia

Abstract

In this paper we propose an efficient multivariate public key cryptosystem based on permutation p-polynomials over finite fields. We first characterize a class of permutation p-polynomials over finite fields $F_{q^{m}}$ and then construct a trapdoor function using this class of permutation p-polynomials. The complexity of encryption in our public key cryptosystem is $O(m^{3})$ multiplication which is equivalent to other multivariate public key cryptosystems. However the decryption is much faster than other multivariate public key cryptosystems. In decryption we need $O(m^{2})$ left cyclic shifts and $O(m^{2})$ xor operations.

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