The National Center for Security in Control Systems for Critical Infrastructure (NCS3) is a collaboration between the Swedish Contingencies Agency (MSB) and the Swedish Defense Research Agency (FOI) to strengthen the security of the systems that constitute critical infrastructure. The work carried out within NCS3 is regulated through assignments from MSB. This report summarizes the assignments agreed upon during 2020. The assignments have been performed by the Department of Defense Analysis and the Department of C4ISR (Command, Control, Communications, Computers, Intelligence, Surveillance and Reconnaissance) at FOI. The topics of the studies performed during 2020 included Vulnerabilities in cyberphysical systems in heavy vehicles, Internet attached ICS systems in Sweden, Electromagnetical threats to wireless systems, Legislation and regulations ,and ICS in medtech. Three training sessions were also arranged by NCS3 during the year.