Iterative Caesar cipher using grayscale image pixel values as keys

The susceptibility of conventional Caesar cipher as a tool for encryption is a known fact not only due to its simplicity but also its practical infeasibilities. The requirement in today's complex age is of a method which has higher effectiveness in terms of being immune to cryptanalysis and at the same time is simple to implement. This paper is about a distinctive methodology by incorporation of a scheme that combines the use of dynamically generated keysets from grayscale images and a modified cipher. The unique aspect proposed yields higher security as each keyset derives its key values from the respective grayscale image which are used iteratively in the modified algorithm. Every iteration in the algorithm makes use of a different key value from the keyset, producing a new cipher-text in each iteration. Cipher-text produced in every iteration is encrypted in the succeeding iteration. This process repeats until all key values are used to obtain a highly-encrypted form of cipher-text. Hence, this sequential and iterative approach is proposed as an effective solution for present-day requirements of information security.