The UN Institute for Disarmament Research and the Center for Strategic and International Studies organized three expert workshops to open and broaden the discussion of international norms for responsible State behaviour in cyberspace and to identify new ideas to support further progress by the international community. The first focused on identification of new norms, the second on the application of international law, and the third on ways to manage the spread of malicious cyber tools. The intent was to build on past progress and to expand the space for international agreement on measures to increase stability and security in cyberspace.