An M3 Public-Key Encryption Scheme

Abstract

It is well known that the RSA public-key cryptosystem can be broken if the composite modulus can be factored. It is nor known, however, whether the problem of breaking any RSA system is equivalent in difficulty to factoring the modulus. In 1979 Rabin [5] introduced a public-key cryptosystem which is as difficult to break as it is to factor a modulus R=p1p2, where p1p2 are two distinct large primes. Esaentially Rabin suggested that the designer of such a scheme first determine p1 and p2, keep them secret and make R public. Anyone wishing to send a secure message H (0 < M < R) to the designer would encrypt M as K, where (Formula presented.) and 0 < K < R, then transmit K to the designer.