Due to the dangers in cyberspace, all countries in the world are facing unprecedented threats to national security. Cyber security is thus elevated to the strategic height of national security.

The traditional cyberspace defense, which is passive defense based on the prior experience, cannot effectively resist the attacks in bugs and backdoors, or deal with infiltrative network invasion which becomes more complicated and intelligent. From the perspective of engineering, there is a dilemma that "the bugs are unavoidable, so are the backdoors".

Bugs and backdoors of existing cyberspace system, which are results from its steady state, similarity, and deterministic, make it easy to be attacked or controlled.

We attempt to take an active defense approach. Our researches focus on creating a dynamic cyber environment by active reconstruction or migration of networks, platforms, systems, software and data, which varies in a way that defenders can control. This approach can break the attack chain relying on certainty and persistency of execution environment, and thus stop the attack, increase the difficulty and cost of attack behavior and reduce the risks in security system.

Theory, Technology and Application of Cyberspace Active Defense.docx.