The digitalisation of railway operations on the basis of the European Train Control System (ETCS) is gaining more and more momentum. This increases the possible attack vectors from a security perspective. The need for a harmonised protection of ETCS and a secure application of existing standards is thus increasing. For this reason, the ERTMS Users Group (EUG) has founded the ERTMS Security Core Group (ESCG), which consists of security experts from the involved infrastructure managers and railway undertakings. One year after its foundation, the ESCG has published comprehensive documents including a security concept, risk assessments and detailed requirements. These are presented by Richard Poschinger (EUG/INCYDE), Christof Jungo (SBB), Ernst Kleine (EUG) and Martin Espenschied (SBB) in the article "Cyber security measures for ERTMS from the rail operators’ perspective" in issue 09/23 of Signal+Draht.