Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS) Authentication Using M2M Certificate
Yuri Poeluev, Warwick S. Ford · 2015
This memo defines Transport Layer Security (TLS) extensions and associated semantics that allow clients and servers to negotiate the use of M2M certificates for a TLS/DTLS session, and specifies how to transport M2M certificates via TLS/DTLS. It also defines the registry for non-X.509 certificate types. The X.509 public key certificate format is overly verbose for Internet- of-Things (IoT) constrained environments, where nodes with limited memory and networks with limited bandwidth are not uncommon. The Machine-to-Machine (M2M) certificate format is a pruned down and encoding-optimized replacement for X.509, which reuses much of the X.509 semantics but reduces certificate sizes by typically 40%.