MULTIPLE DOMAIN DATA COMMUNICATION

摘要

This invention concerns a multiple domain data communication method and network. …An embodiment of the invention provides communication security for data transmissions between different domains of a multiple domain communication network where each domain includes a host system i, j, k and its associated resources of programs and communication terminals T. The host systems and communication terminals include data security devices 11, X each having a master key 13 which permits a variety of cryptographic operations to be performed. When a host system in one domain wishes to communicate with a host system in another domain, a common session key is established at both host systems to permit cryptographic operations to be performed. This is accomplished by using a mutually agreed upon cross-domain key known by both host systems and does not require each host system to reveal its master key to the other host system. The cross domain key is enciphered under a key encrypting key designated as the sending cross domain key at the sending host system and under a different key encrypting key designated as the receiving cross domain key at the receiving host system. The sending host system creates an enciphered session key and together with the sending cross-domain key performs a transformation function to reencipher the session key under the sending cross domain key for transmission to the receiving host system. At the receiving host system, the receiving host system using the receiving cross-domain key and the received session key, performs a transformation function to reencipher the receives session key from encipherment under the sending cross domain key to encipherment under the receiving host system master key. With the common session key now available in usable form at both host systems, a communication session may be established and cryptographic operations can proceed between the domains of the two host systems.