Cryptography at its very core is nothing but math - pure, simple, undiluted math. Math created algorithms that are basics for various encryption algorithm. Encryption is a method in which user’s confidential data or private data is encoded to cipher text and this text can be read only if it is decrypted by authorized user using the right key. Cipher text can be decoded back to plain text, only by the authorized users using a right key. Various encryption algorithm are used to encrypt the plain text to cipher text and the cipher text is decrypted back to plain text by authorized user using right key. The symmetric key algorithm uses the same key to encrypt the plain text and decrypt the cipher text. In this paper we have proposed new symmetric algorithm using ASCII value. The plain text using key and ASCII values is converted to cipher text. Encryption algorithm sends cipher text and minimum value to the authorized receiver. Receiver decrypts the cipher text to plain text using same key and minimum value. In this algorithm sequence of five pseudo random number is generated and sum of this five pseudo random number is added to the obtained decimal value. Seed to generate common sequence of pseudo random number is kept secret between sender and receiver. Proposed algorithm support variable key length and plain text size. This algorithms performs faster when text is small message, but the execution time increases as the plain text size increases. This algorithm can be used to send small messages in a secured way. .