Blockchain technology, especially its open, unpermissioned variant was designed to operate without any central legal authority (Walport 2015), making its regulation challenging for a regulatory framework that is essentially geared towards centralised actors. The regulatory history of the digital networks, such as peer-to-peer file sharing networks suggest that on the long run few technologies (Bodó 2014a) can stay totally immune to regulation (Giblin 2011; Lessig 1999). The effectiveness of a policy response to a quickly developing technology depends on its ability to simultaneously address a substantive and a technical challenge. The substantial challenge is finding the right balance between an innovation-friendly hands-off approach, and other, more pressing policy priorities, such as combating cybercrime, or providing more efficient, transparent, accountable public services. The technical challenge that regulatory authorities (on national, European and international levels) face is how to avoid badly chosen policy tools which result in a regulatory stalemates (as is the case with online copyright enforcement (Bodó 2011)), or leave substantial gaps in regulation (as in the case of protecting users’ privacy online). WP5 will (1) create an inventory of policies by collecting (publicly accessible) policy documents, background studies, legal texts, court cases, and the texts of legislative processes (including documents of the political debate) from the EU and the US, that address blockchain technology. Using this material alongside with the empirical evidence gathered in the other two WPs, WP5 will then (2) provide a legal analysis and, where possible, (3) compare these policies, in terms of their potential impact, and effectiveness in managing the aforementioned technical and substantive challenges. Based on this comparative assessment, the WP will work towards (4) new policy tools within the EU Acquis to balance the risks and promises of blockchain technology.