Abstract: In a client/server system, a method and apparatus for handing requests for access to a host resource purportedly on behalf of a client from an untrusted application server that may be capable of operating as a “rogue” server. Upon receiving a service request from a client, an untrusted application server creates a new thread within its address space for the client and obtains from the security server a client security context, which is anchored to the task control block (TCB) for that thread. The client security context specifies the client and indicates whether the client is an authenticated client or an unauthenticated client. When the application server makes a request for access to a host resource purportedly on behalf of the client, the security server examines the security context created for the requesting thread.

Abstract: A system for authenticating a first entity to a second entity and for simultaneously generating a session key for encrypting communications between the entities. The first entity generates an authentication value by encrypting time-dependent information using a long-lived secret key shared by the entities and transmits the authentication value to the second entity. The first entity independently encrypts other time-dependent information using the long-lived key to generate a session key that cannot be derived from the authentication value without the long-lived key. Upon receiving the transmitted authentication value, the second entity checks the transmitted authentication value using the shared long-lived key to determine whether it is valid. If the authentication value is valid, the second entity authenticates the first entity and generates an identical session key from the same shared secret information and time-dependent information.