A Review of RSA and Public-Key Cryptosystems

Abstract

The idea of information security lead to the evolution of Cryptography. In other words, Cryptography is the science of keeping information secure. It involves encryption and decryption of messages. Encryption is the process of converting a plain text into cipher text and decryption is the process of getting back the original message from the encrypted text. Cryptography, in addition to providing confidentiality, also provides Authentication, Integrity and Non-repudiation. The crux of cryptography lies in the key involved and the secrecy of the keys used to encrypt or decrypt. Another important factor is the key strength, i.e. the size of the key so that it is difficult to perform a brute force on the plain and cipher text and retrieve the key. In this paper we study and analyze the RSA cryptosystems – a public-key cryptographic algorithm - a system that uses two sets of keys; one for encryption and the other for decryption.

Key Words: Public-key cryptography, DH, RSA, Internet Security and attacks, Digital Signature, Message digest, Authentication, Secure Socket Layer (SSL)

Botswana Journal of Technology Vol.13(2) 2004: 1-11