Encryption-Based Protection Protocols for Interactive User-Computer Communication.

摘要

This thesis develops a complete set of protocols,which utilize a block cipher, e.g.,the NBS data encryption standard,for protection interactive user-computer communication over physical unsecured channels. The use of the block cipher protects against disclosure of message contents to an intruder,and the protocols provide for the detection of message stream modification and denial of message service by an intruder. The protocols include facilities for key distribution,two-way login authentication, resynchronization following channel disruption,and expedition of high priority messages. The thesis presents designs for modules to implement the protocols,both in a terminal and in a host computer system,and discusses the results of a test implementation of the modules on Multics. (Author)