Graph Theory is one of the significant and important areas in Mathematics, which is used in Network Security. Cryptography is art of science to achieving security by encoding message to make it non-readable (secretive) to unintended users. Many techniques are presents to encrypt plain text and convert it to the cipher text [2]. Any cryptographic scheme is secure if and only if it is unbreakable in reasonable time, using feasible resources in spite of the intruder's being aware of the encryption and decryption algorithm and size of the key. In the proposed algorithm, adjacent matrix of graph can be used to obtain key for encryption and decryption which is safer compared to other keys.

Graph theory has many applications in computer science. But it can also be used to make the data secure. Sometime it is used in networking for many purposes. Cloud computing provide user many services like SAAS, IAAS and PAAS. But with many benefit still cloud providers are not too much confident about the security aspects. As for the data storage, cloud data center depends upon third party involvement. So there is need of an algorithm that can authenticate sender and receiver before any transaction between user and third party. The Proposed algorithm uses the adjacency matrix to make the data secure. OTP is one of the attractions used before any transaction.