Cascaded authentication

The author addresses a problem that has arisen in building distributed systems in which incomplete trust exists and program composition is necessary. The problem is to permit authentication for both access control and accounting when cascading invocations. The problem can be identified as one of providing cascaded authentication. The author has developed a mechanism she calls passports that are passed along with each stage of the cascade and digitally signed at each transition. The information thus signed is that which is critical to the authentication. The focus is both on recognizing the problem and on devising a solution that is efficient enough to be usable, although there will be some cost associated with such a mechanism.<>