The security issues set by the global digitization of our society have had, and will continue to have, a crucial impact at all levels of our social organization, including, just to mention a few, privacy, economics, environmental policies, national sovereignty, medical environments. The importance of the collaborations in the various ?elds of computer s- ence to solve these problems linked with other sciences and techniques is clearly recognized. Moreover, the collaborative work to bridge the formal theory and practical applications becomes increasingly important and useful. In this context, and since France and Japan have strong academic and ind- trial backgrounds in the theory and practice of the scienti?c challenges set by this digitized world, in 2005 we started a formal French-Japanese collaboration and workshop series on computer security. The three ?rst editions of these French-Japanese Computer Security wo- shops in Tokyo, September 5-7, 2005 and December 4-5, 2006 and in Nancy, March 13-14, 2008 were very fruitful and were accompanied by several imp- tant research exchanges between France and Japan. Because of this success, we launched a call for papers dedicated to computer security from it's foundation to practice, with the goal of gathering together ?nal versions of the rich set of papers and ideas presented at the workshops, yet opening the call to everyone interested in contributing in this context. This v- ume presents the selection of papers arising from this call and this international collaboration.