Patent ID: 7346771

Claim:
A method comprising: establishing a portion of a chained authentication system at a second router located in a second autonomous system, the chained authentication system including the second autonomous system and a first and a third autonomous system, each of the first, second and third autonomous systems having a trust relationship with at least one of the other autonomous systems of the chained authentication system and each autonomous system sharing cryptographic information related to its trust relationships with the at least one of the other trusted autonomous systems, establishing a portion of the chained authentication system comprising: at the second router, receiving third cryptographic information for securely communicating with a third router located in the third autonomous system; receiving at the second router first cryptographic information for securely communicating with a first router located in the first autonomous system; and after receiving the first and third cryptographic information at the second router, sending a first routing protocol exchange message to the first router comprising the third cryptographic information for the third router, the first routing protocol exchange message including routing information for updating a routing look-up table corresponding to the first router.