  Caesar cipher is an ancient, elementary method of encrypting plain text
message to protect it from adversaries. However, with the advent of powerful
computers there is a need for increasing the complexity of such algorithms. In
this paper, we contribute in the area of classical cryptography by providing a
modified approach and expanded version for Caesar cipher using knowledge of
mathematics and computer science. To increase the strength of this classical
encryption technique we use the concepts of affine ciphers, transposition
ciphers and randomized substitution techniques to create a cipher text which is
nearly impossible to decode. We also increase the domain of characters which
Caesar cipher Algorithm can encrypt by including all ASCII and extended ASCII
characters in addition to alphabets. A complex key generation technique which
generates two keys from a single key is used to provide enhanced security. We
aim to propose a modified version of Caesar cipher substitution technique which
can overcome all the limitations faced by classical Caesar Cipher.
