Optimization of Hybrid Encryption Algorithm for Secure Communication System

Cryptography is the art or technique of encoding a message by a sender in such a manner that only the intended receiver can decode it. It is a technique by which we can secure our data from attackers. With the advent use of the Internet, the situation is very different now. The Internet is used by a large number of users, and virtually all attacks originate from within the network. Strong encryption algorithms and optimized key management techniques help in securing the data and achieving confidentiality, authentication, and integrity of data. The algorithm encrypts the message character by character using stream cipher, and the number of keys depends on the size of the message. This paper proposes a hybrid cryptographic algorithm which uses both substitution and transposition techniques to address the security of data or plaintext. Decryption will be done at receiver's side in the reverse way of encryption. Using this technique, we can protect the data and avoid unauthorized access to an unsecure communication channel. The number of keys is not predefined and it depends on the size of the plaintext making the encryption technique more secure.