Multiple Caesar Cypher Encryption Algorithm

Abstract

The Caesar cipher has always been the major reference point when cryptographic algorithms (also called ciphers) are discussed. This, probably, is due to its being an age-long cipher. It may also be owing to the belief that the Caesar cipher was the first cipher used ever. Caesar cipher operation is based on shift-by-3 rule which makes its breaking obviously easy since an exhaustive key search of the other 25 keys can be conveniently performed. Ipso facto, an investigation into an enhancement of this too-simple-to-crack cipher is invariably necessary and ultimately important. This study is, therefore, concerned with developing a new enhanced model of Caesar cipher for a better security using multiple encryption technique, whereby an already-encrypted message is encrypted one or more times using the same or different algorithm. The new model works by wrapping a plaintext message in three cryptowrappers and each encryption/decryption phase uses a different shift key from the other. The model supports both uppercase and lowercase characters. However, the model does not encrypt/decrypt numbers, special characters, whitespace, and file types such as word document, binary, or pdf files, but only text files. Most importantly, the new enhanced model is able to provide a better security of message by encrypting a plaintext message three times; in this way, brute forcing or an exhaustive key search will be difficult to perform; thus, making cryptanalysis almost a mirage!