38 researchers affiliated with over 25 different institutions in 7 countries met during Dagstuhl
Seminar 18461 for discussing open problems regarding “Blockchain Security at Scale.” The seminar was split into eight blocks of two presentations each. The mode for each talk was 15 minutes of blackboard-only presentation followed by 30 minutes of discussion. Discussions not fitting into this limit were resumed in smaller break-out groups. This report documents the scheduled talks as well as the improvised sessions for in-depth discussion.