Abstract: The invention provides an authentication scheme that allows networked devices to establish trust in connection with the exchange of keys pursuant to an asymmetrical cryptographic technique, such as Diffie-Hellman. The invention provides a technique, referred to as offline key establishment, that establishes a trust relationship between two networked devices that use Diffie-Helman. Offline key sharing provides for the exchange of authentication information using a separate channel which, in the preferred embodiment does not constitute an IP connection. Thus, while communications between networked devices may ultimately proceed via a network connection, trust between the networked devices is established via a separate, offline channel, such as a telephone call or email message. The use of offline key establishment allows for such features as one way key sharing; and addresses situations where one party to the exchange does not want to share all of his keys, but just one or two keys.