Cryptography comes from the Greek words for “secret writing”. The plain text is encrypted into the corresponding cipher text, using an algorithm and a key. Substitution and Transposition are two techniques used for converting data into non-readable form. Caesar Cipher is an example of substitution technique. In this paper we have proposed a cipher that uses basic encryption techniques of substitution and transposition. A single columnar transposition followed by a double substitution is applied on a Caesar cipher in order to make it a stronger and a more secure cipher.