Abstract: Cryptography is an art and science. It is a playing major role in information and security division. The main aim of the cryptography is protecting the data from unauthorized users or hackers. “Cryptography is subject contains two parts one is encryption and another one decryption. Encryption is a process converting the plain text to cipher text using some keys. Decryption is a process of converting the cipher text to plain text using the keys”. There are several algorithms in cryptography to encode and decode the data based on the key. This paper discusses types of cryptography and different keys in cryptography. The paper can give brief description about symmetric key algorithms and we are proposing new algorithm in symmetric key cryptography. The proposed algorithm contains two levels of Exclusive OR (XOR) operation. This algorithm is useful in transmission of messages and data between one user and another.