Research On Key Recovery System Based On Distributed Computing

With the popularity of the Internet and information technology, key recovery, as an important branch of cryptography, takes great weight in computer data and electronic evidence. In the determination or disposal of various types of disputes and the process of criminal cases, electronic evidence has become an important technical means as well as important evidence. However, encryption of electronic documents brings new technical requirements to electronic evidence in the stage of evidence analysis; we can use brute force method to achieve this. Brute force key recovery in symmetric cryptography and asymmetric cryptography are both effective and it has a natural convenience to be implemented concurrently. Especially in today's society, the rapid development in computer speed and the Internet make brute force key recovery possible. The use of brute force to achieve key recovery are mainly classified into two areas: hardware implementation and software implementation. This paper uses software method in the design of the key recovery system and it mainly includes the following parts:(1) Describes the methods used in and technical implementation of key recovery system, including the conceptions of brute force and distributed computing. Brute force is usually achieved by two methods: software crack and hardware crack. There are also descriptions of system architecture, operation mode, communication protocols of key recovery system.(2) We analyzed the encryption theory of office 2007 and office 2003 and key space traversal algorithm, introduced the design requirement and methods in the server-side console and client-side crack in the designing of C/S based key recovery system. After the simulation of both the above methods, we analyzed the crack speed.(3) After analyzed the central module of C/S based key recovery system, we use cloud computing to improve its drawbacks. We also introduced core technology of cloud computing, distributed file system and Map-Reduce programming model, before the proposal of key recovery model based on cloud computing.