The Design And Implementation Of Peer-to-peer Encrypted Short Message System Based On Android

The use of short message is more and more frequent, and the using range is becoming wider.There is a wealth of information contained in the messages.The existing SMS systems cannot ensure its safety, the design of using store-and-forward mode is vulnerable to man-in-the-middle attack and has information security threats.To solve the above problems, a SMS peer-to-peer encryption system is designed based on the Android platform.By reading a large number of papers can have comprehensive understanding of the current research on the SMS system service and its security. And the Android source code and its API not only introduces the process of Android mobile phone short message business,but also the way the Android mobile phone storing the sending and receiving messages.Symmetric encryption algorithms are chosen to design the system,by comparing the DES, 3 DES, AES algorithm,finally the AES algorithm performs better.In the process of design, the system avoids to negotiating the key in advance, and use the time and mobile phone numbers to generate the key. Before sending message, the content uses AES encryption algorithm to encrypt, and then the results using Base64 algorithm to deal with unvisitable characters. The system can have one more contacts, and can send large length of messages.In this paper, the Android SMS peer-to-peer encryption technology in the maintenance of SMS security has a good practicability. By testing the system performance, the system can send and receive encrypted messages without interfering with the normal message. Tests also shows that after encryption and coding,the length of message increases, it reduces the system transmission capacity.In the future research the research should be focused on the improvement of the performance of the message transmission, and the UI of the should be improved.