Currently there is an internal class inside of DtlsServer used to look up user keys called MyIdentityManager. I would like a way to override the behavior to supply a different user key storage mechanism. Currently this is not possible since it is created directly on line 24 of DtlsServer.cs in the constructor. An alternate implementation of DtlsServer is also not able to be injected since it is created directly at line 134 of DTLSSession.cs. Just wanted to mention this in case you are working on some refactoring in this area for the next version.