Suneetha, CH.Sravana Kumar, D.Sirisha, P.Sandeep, KM.2023-07-312025-03-312023-07-312017-092231-5373https://dspacenew8-imu.refread.com/handle/123456789/2306Extensive growth of telecommunication network provides easy and quick techniques of communicating the information. Rapid development of information technology has given the scope to huge range of new possibilities of internet hacking. Solution to the security problems expanded the field of cryptography. The present paper describes a block cipher mechanism for message confidentiality and authentication using simple arithmetic, logical operations and one-way cryptographic hash functions in two different stages. Agreed upon primary or Master key is used to generate number of sub keys for encrypting different message blocks to extend the lifetime of the master key using some permutation function.enArithmetic operationEncryptionDecryptionOne-way hash functionArticle