Abstract: In various embodiments, a server stores a set of cryptographic keys associated with a client that includes a server-stored bootstrap key, a server-stored authentication key, and a server-stored proposed key. The server receives an authentication request from the client that includes a client-indicated bootstrap key, a client-indicated authentication key, and a client-indicated proposed key. The server makes a determination that the client is authenticated based in part on whether there is a match between the client-indicated authentication key and either the server-stored authentication key or the server-stored proposed key. The server provides, based on the determination, an authentication response to the client indicating that the client has been authenticated.

Abstract: This invention relates to a thermal transfer donor element comprising a support having thereon a dye layer comprising a dye dispersed in a polymeric binder, the dye layer being capable of being thermally transferred to a receiver element, wherein the polymeric binder is a phenoxy resin.