ABSTRACT

Today data communication is a modern technology that contains a powerful computer processor to exchange information. But brute force attacks are made to break the encryption techniques and these attacks are the main drawbacks of older algorithms. This paper is concerned with the development of a computerized data encryption and decryption system based on cryptographic algorithms that is faster, better immune to attacks, more complex, easy to encrypt and many more advanced security feature included. This project work is designed and developed for a secure messaging. The application is well featured and provides encryption/decryption that can protect message from unauthorized access and disclosure over networks. To send message, a recipient or registered user types and encrypts a text message using keyword monoalphabetic substitution algorithm with a key, selected from key list. The encrypted message is stored in the database and receiver's inbox with serial number of key (not the value). The receiver, after logging into his/her own account, selects the key value and then decrypts the encrypted message with the key to see the original message. Comparing it with other messaging systems, the proposed secure messaging system can be used for chatting, messaging, and real time file sharing in both web and intranet platforms