ABSTRACT:
Information Security is an important issue of concern in communicating the data between the parties. Cryptographic algorithms emerged as a solution and have contributed a major role in information security system. Most of the cryptographic algorithms rely on a key for performing encryption and decryption. The key used along with the algorithm plays a vital role in ensuring the security and confidentiality of the text that is transmitted. In this work, we propose a new technique to generate a new key from the given key using different tree structures. If the key size is less than 128 bits, the given key is converted to 56 bits and then the given text is encrypted with DES followed by Blowfish algorithm. If the key size is greater than 127 bits, the given key is converted to 128 bits and then the given text is encrypted with AES followed by the RC6 algorithm. The reverse process is carried out for decryption in both the cases.