Network Clock Synchronization And Its Security

Time synchronization is not only a classical issue in the distributed operation system, but also one of the kernel techniques of the distributed applications. As the swift and violent development of computer and network communication technology, the clock synchronization between network nodes in an asynchronous environment becomes more and more important. Meanwhile, the new content and broad range are added in this research area of clock synchronization. Time synchronization security is the one. In order to avoiding evil or devil malicious attack,it is necessary for client to authenticate server proventic or not.This paper mainly consists of three parts: the first part introduces the related content of clock synchronization,including the concepts of physical clock, logical clock,universal time coordinated and atomic second.The second part introduces synchronization sources, synchronization method and synchronization model of time clock synchronization system, and its working mode. Then the working principle and implementation method of network time protocol is analyzed. At the same time,client software based on Java language is developed and its core code is analyzed.The third part is the discussion about clock synchronization security. Apart from introducing resistance mechanism, possible encountering malicious attack and presumed required limitation of network time protocol, the feasibility about digital certificate applied to time synchronization is analyzed. Lastly,the characteristic and authentication ability of autokey is mentioned.