An Extension of Vigenere Technique to Enhance the Security of Communication

Security is one of the most important issues in modern world. With the fast growing of internet and networked system, its applications such as banking, e-commerce, government etc. demand for effective raw material of information is growing rapidly. Cryptology deals with the data communication to transfer data in secure manner from place to another. It is the system by which cryptography and cryptanalysis are combined. It consists of two matching fields of study that are cryptography and cryptanalysis. We will discuss the cryptanalysis of Poly-alphabetic substitution cipher by applying the modified Vigenère table in which message is presented to encrypt and decrypt the data. Time so change, if we apply this process the brute force attack in the cryptanalysis is impossible.