New security features in DLMS/COSEM — A comparison to the smart meter gateway

In this paper we describe the new security features of the international standard DLMS/COSEM that came along with its new Green Book Ed. 8. We compare them with those of the German Smart Meter Gateway approach that uses TLS to protect the privacy of connections. We show that the security levels of the cryptographic core methods are similar in both systems. However, there are several aspects concerning the security on which the German approach provides more concrete implementation instructions than DLMS/COSEM does (like lifetimes of certificates and random generators). We describe the differences in security and architecture of the two systems.