Research On Key Techniques Of Instant Messenger Protocol Analysis And Surveillance

Today, with the rapid development in Instant Messenger (IM) software, on the one hand, the convenient and efficient service it provides facilitates everyone's daily life, work and study; On the other hand, it also poses new problems for security management personnel.IM software has various problems like endangering national security, disclosure of state secrets and other business realities. In this thesis, on the basis of a large number of experimental data, MSN protocol analysis is done on text, voice and video.Three mainstream Instant Messenger software (MSN, ICQ and Yahoo) are involved in a comparative study. LEX lexical resolution technique is studied in depth, and an analytical model based on LEX is presented. We also design the framework of IM information surveillance system. Detailed descriptions are made on the in-depth design and implementation of MSN data reception, TCP data reassemble, MSN protocol resolution, SIP protocol resolution and message data restore. Finally under simulation environment, a large number of experimental data shows text and voice message can be correctly resolved and restored.