The development of the Key Management System (KMS) for the European Train Control System at
application level 2 is the subject of this study. All cryptographic processes utilized in communications between
entities of the stationary and mobile components of the European Train Control System (ETCS) over the
Global System of Mobile for Railway (GSM-R) need the KMS solution. The authors highlight the KMS
proposal, which is based on symmetric cryptography approaches. The potential for key creation and
distribution within a single domain as well as across ETCS domains is resolved in detail.