For decades, Computer and Information Security studies have been driven by core concepts such as Confidentiality, Integrity, and Authentication. What would be the core concepts that will drive the study of the emerging discipline of Cybersecurity? In this talk, I will present the novel concept of Cybersecurity Dynamics, which has a great potential in formulating a foundation for the emerging Science of Cybersecurity. I will start with a conceptual exploration, highlight some preliminary results toward the ultimate goal, and discuss some technical barriers that must be adequately addressed before we can achieve the ultimate goal. Please refer to http://www.cs.utsa.edu/~shxu/socs/index.html for more information about this exciting research endeavor.