Abstract

Introduction An United States Presidential announcement on Apr. 16. 1993. referred to as the “Clipper initiative." called for the development of a hardware implementation of a classi? ed encryption algorithm called “Skipjack". The Presidential announcement characterized the Skipjack algorithm as being “signi? cantly stronger than those currently available to the public.” The hardware implementation of Skipjack would also include a capability called “key escrow” which allows the government to recover the keys used for data encryption. The integrated circuit chip which implements the Skipjack algorithm is called the “Clipper chip” and/or the" Capstone chip”.
The Clipper initiative (particularly the key escrow feature) attempts to preserve the ability of law enforcement and national security to intercept and exploit the contents of communications while providing law-abiding citizens with an encryption system much …

Date

1997

Authors

SB Lipner, DM Balenson, CM Ellison, ST Walker

Inventors

Steven B Lipner, David M Balenson, Carl M Ellison, Stephen T Walker

Patent_office

US

Patent_number

5640454

Application_number

08715377