With the rapid development in the technology, Encryption is one the most power full approach to achieve data security and privacy. Data Encryption techniques is used to hide the original content of a data in such a way that the original information is recovered only through using a key known as decryption process. The objective of the encryption is to secure or protect data from unauthorized access in term of viewing or modifying the data. Encryption can be implemented occurs by using some substitute technique, shifting technique, or mathematical operations. By applying these techniques we can generate a different form of that data which can be difficult to understand by any one. The original data is referred to as the plaintext and the encrypted data as the cipher text. Several symmetric key base algorithms have been developed in the past year. In this paper we proposed a comparative study over symmetric key based algorithm using some parameter like algorithm strength, key size, key type attack type etc.

Symmetric Encryption Decryption Substitution Transposition Plaintext Chipper text.