A New Modified Playfair Algorithm Using CBC

Security is required in order to defend information from unauthorized person on the network. Therefore, securely exchanging data over the internet is vital. In this context, cryptography is used that transmute facts from its under stable form into an indecipherable form by using various encryption techniques. Play air cipher is the form of block cipher which has no limit on the number of characters in a message it can do, but it operates on block of characters encrypting and decrypting two characters at a time cipher. In this, the plain text digraphs are converted to cipher text digraphs and vice versa using a pre-shared key. This is achieved by performing several operations column wise row wise and by creating rectangular form. This paper deals with a new solution approach to overcome the shortcomings of the Play air algorithm. In this paper, the presented Play air CBC encryption mechanism makes the cryptanalysis complex. The encrypted text obtained is almost unreadable.