In recent years there is drastic progress in Internet world. Sensitive information can be shared through internet but this information sharing is susceptible to certain attacks. Cryptography was introduced to solve this problem. Cryptography is an art and the science of creating the secret code. Substitution and the transposition are the two technique use for encoding and decoding the text. So when we these two technique individually it is easy to track. This can be overcome by combining these two techniques. So the Caesar cipher from substitution and the keyed transposition and the columnar technique from the transposition can be used. So by combining these two techniques the fundamental weakness can be overcome and the cipher text becomes very hard to track.