Registration of non-configured network devices in a distributed network is
facilitated by a method of distributing cryptographic keys. A
non-configured first device seeking to communicate securely with a second
device acquires knowledge of a trusted registration service. The first
device registers with the registration service and obtains a longer-lived
symmetric key. Using the longer-lived key, the first device authenticates
itself to a key management service, and receives a shorter-lived
symmetric key encapsulated in a ticket that includes policy information.
A second device carries out the same preparatory process. Using its
ticket containing the shorter-lived key, the first device requests the
second device to obtain a session key on behalf of both. The second
device presents its own ticket and that of the first device to the key
management service to authenticate the shorter-lived key, and then
obtains a session key for use in communications among the first and
second devices. The first device and second device then communicate by
encrypting communications with the session key, and without further
contact with the key management or registration services or any other
online authoritative server or key database. Thus newly deployed network
devices may be positively identified, registered in the network, and
subjected to key schedule or other key management policies.