The Design and implementation of encrypted chat system based on Linux
Abstract
Along with Computer becoming more and more popular and Internet technology developing rapidly, a lot of People began to use the IM(chat program). Chat program brings people more convenience, but at the same time, security problem existed. The traditional chat program sends the message by plain text, which open the door for the bad man. This encrypted chat system is right based on the point. The system is in C/S architecture using socket based on Linux. The server program serves each client in the way of establishing thread and is responsible to transfer message. The DES algorithm and RSA algorithm are used to encrypt in this program. The basic principle is that the server generates RSA public key and private key and client generates DES symmetrical secret key. Firstly, the server sends the public key to client, and then client sends it back after encrypting DES secret key. Secondly, the Server uses local private key to decode to obtain the DES private key. After then, the message is sent after encrypted by DES secret key. So the plain text can be encrypted effectively and sent in channel in security.
