This paper presents a peer analysis in the field of encryption algorithms, concentrating on private key block ciphers which are generally used for bulk data and link encryption. We have initially surveyed some of the popular and efficient algorithms currently in use. This paper focuses mainly on the different kinds of encryption techniques that are existing, and comparative study together as a literature survey. This study extends to the performance parameters used in encryption processes and analyzing on their security issues. Cryptography is the practice and study of hiding information. Prior to the modern age, cryptography was almost synonymous with encryption i.e. the conversion of information from a readable state to unreadable state. In order to avoid unwanted persons being able to read the information, senders retain the ability to decrypt the information. There are three types of Cryptography. They are Asymmetric-key cryptography, symmetric key cryptography and hashing. Encryption methods in which both the sender and receiver share the same key are referred to as symmetric key cryptography. This paper provides a comparison between symmetric key algorithms such as DES, AES, and Blowfish. The comparison is made on the basis of these parameters such as block size and key size.