Cryptographic Coding for Data-Bank Privacy

This report deals with a secure digital network concept in which computers communicate with computers. It is envisaged to be fully automatic in all aspects, including the switching at the nodes. All operations are protected by cryptographic coding techniques.

The security functions are broad in concept and include not only message secrecy in the usual sense bur also high security verification. The latter provides assurance that all communications are of legitimate origin and rejects all data which are suspected as having been corrupted by accident or intent.

The cryptographic techniques employed are time independent ciphers which encrypt large blocks of binary digits. A special manner of using such block codes, called step coding makes possible a variety of super and multiple level enciphering techniques, previously not possible.

Although the concept is very broad in scope and applicability, it has been found useful to illustrate it in terms of a conceptual data bank scheme.