Secure comms claimed with no encryption

By Loring Wirbel,
EE Times
October 29, 2004 (3:02 PM EDT)

Colorado Springs, Colo. The developer of the eponymous "Gold codes" has demonstrated a self-synchronized receiver technology that he says will enhance security in wireless LANs, cellular networks and ultrawideband systems. Robert Gold's company, Robert Gold Comm Systems Inc. (Carlsbad, Calif.), has demonstrated a two-receiver system to the U.S. Air Force, and is licensing its software code to semiconductor manufacturers.

Gold is well-known in RF and DSP algorithm circles for his work in the 1980s on an algorithm that uses sequences of pseudorandom numbers that can be generated with two feedback shift registers. These "Gold codes" provide autocorrelation and cross-correlation for wireless networks and have been used within in-building wireless radio networks, UMTS digital cellular networks and the GPS satellite system.

Gold's current work stemmed from an Air Force basic-research contract to explore ways to improve the security of all spread-spectrum systems, whether direct-sequence or frequency hopping. Gold said he has developed an efficient module of embedded software for transmitters and receivers that allows them to synchronize their patterns in milliseconds without the use of external clocks. Software for the self-synchronizer occupies only 7,000 lines of code in a Windows environment, and can be made even more compact when compiled for embedded environments.

"It represents very little overhead, even in constrained environments like handsets," Gold said.

Internet orientation
Gold's company completed a study under the Air Force's Small Business Innovative Research program that led to delivery of a two-receiver frequency-hopping test bed. The contract was conducted under the RF sensor division of the Electronic Warfare Technology Branch at Wright-Patterson Air Force Base in Ohio.

The algorithm has several properties useful for ad hoc Wi-Fi radio networks and police/fire radio using virtual private networks: Communications can be secure without the use of encryption; receivers can be addressed individually or in selected groups, allowing the use of Internet Protocol broadcast and multicast methods; a receiver can enter and leave the network at any time; and a transmitter will securely confirm group membership. The last two factors could be of particular interest in emerging voice-over-IP networks that span LANs and WANs, Gold said.

While the Air Force is exploring a range of open and classified applications for the technology, Gold's company ( is free to license the basic algorithms for commercial applications.

Copyright 2003 CMP Media, LLC