Abstract

The problem faced with symmetric ciphers has always been key exchange. Hellman and Diffie (1976) proposed the idea for key exchange (public key cryptography). Their idea was based on the difficulty in inverting certain mathematical functions; one way functions. The RSA was one of the first practical solutions of key exchange. This paper identifies one way functions and their corresponding public key encryption system, with emphasis on the RSA.

Key words: Public key cryptography, RSA, one way functions, digital signatures, cryptanalysis, encryption, decryption.