Abstract: Encryption is a process of generating secrect text from the input text using a secret key and a encryption algorithm. Input text is refered to as plain text and the secret text generated is known as cipher text. Encryption algorithms are mainly divided into two categories which are symmetric key encryption algorithm and asymmetric key encryption algorithm. In Symmetric key encryption algorithm the same key is used by both sender and receiver but in asymmetric key algorithm sender and receiver both uses the different keys. In this paper, we present a technique based on symmetric key encryption algorithm which uses ASCII vales of input text to encrypt the data. Text data encryption techniques are very useful in data communication where one user want to send some secret messages to another users.