Continuations. Jmx. JAAS Reference Guide. The key JAAS class is javax.security.auth.Subject, which represents a grouping of related information for a single entity such as a person. It encompasses the entity's Principals, public credentials, and private credentials. Note that the java.security.Principal interface is used to represent a Principal. Also note that a credential, as defined by JAAS, may be any Object. Brian Goetz: Publications. xSocket.