Nuclear disarmament is a laborious process that extends over decades. It can only succeed if all participants have a growing sense of confidence that the zero condition can be reached and verified without any uncertainty. A high degree of transparency is needed in order to place this confidence on a firm foundation. The present report calls for the step-by-step introduction of a comprehensive register of fissile material and nuclear weapons which constantly accompanies the disarmament process. Specific proposals are made for how to realize the first step, where such a register could be negotiated, and by whom it could be supervised.