Nuclear disarmament is a long-drawn process that might drag on for decades. This process can only be successful if the confidence, that zero nuclear weapons is possible and can be verified free of doubt, will continuously grow among the involved parties. In order to put this confidence on solid ground, a high level of transparency is required. In HSFK-Report 10/2009 Transparenz für die kernwaffenfreie Welt. Konzepte für ein Kernwaffen- und Spaltmaterialregister (Transparency for a nuclear weapon free world. Concepts for a nuclear weapons and fissile material register) Harald Müller and Annette Schaper plea for a step by step implementation of a complete register for nuclear weapons and fissile material supporting the process of disarmament. The authors make concrete proposals regarding the realisation of the first steps, the place for negotiations of such a register and by whom it should be supervised.