GTE demos encryption capability for cellular net
- By L. Scott Tillett, L. Scott Tillett
- May 10, 1998
GTE Government Systems announced last month that it had successfully demonstrated the first use of a promising computer algorithm for national security over a commercial cellular network.
The demonstration represents only one segment of a broad National Security Agency initiative known as "Condor," which seeks to foster industry development of highly secure products and networks that the national security community— from spies to soldiers in the field— can use for voice and data communications.
Condor's broader aim is to jump-start secure wireless products that national security agents can use with any existing wireless network in the world— be it a standard analog cellular network in Eastern Europe or a digital satellite communications network in the United States.
"Condor is important to the United States," said Judy Emmel, an NSA spokeswoman. "The increasing reliance on unprotected, commercial, mobile wireless systems means that our national leadership, warfighters and law enforcement officials who are using these systems are at risk."
Key to bringing the Condor vision to reality is digitization and encryption. And a host of companies— including GTE as well as Motorola Inc., Qualcomm Inc., L-3 Communications Corp. and Hughes Global Services, a division of Hughes Space and Communications Co.— are developing products and plans for Condor, NSA said.
What GTE has used to give wireless users a glimpse of NSA's Condor vision is an encryption algorithm created by Texas Instruments Inc. and Atlantic Signal Processor. GTE coupled the algorithm— the 2,400 bits/sec Mixed Excitation Linear Prediction (MELP)— with a standard cellular phone and a processor to digitize speech and then encrypt it. GTE used identical equipment on the other end of the call to decode it.
Essential to the demonstration, which was given in late February at the Secure Network Symposium in Dallas, was the ability to show that voice communication could be digitized and encrypted with as high a degree of quality as secure communications under current military methods, which use an algorithm twice as big as MELP.
"With half the bandwidth, we get the same kind of performance, and that allows the government to use more of its channels," said Bob Dutton, vice president and general manager for information processing and security systems at GTE Government Systems.
But the security issue is what drives Condor. "As soon as it hits the air, [a standard cellular call] is subject to interception by unfriendly parties," Dutton said. That is a concern for the military as it seeks to rely more on existing wireless networks rather than build its own.
The wireless industry agreed that wireless communications are not as secure as they could be.
"The amount of security varies widely with the kind of phone you have," said Rick Kemper, director for secure systems at the Cellular Telecommunications Industry Association. "From a user perspective, I suppose the industry association's advice to the user is, 'Don't say anything on an analog cell phone that you wouldn't say in an elevator.' "
As Condor evolves, vendors are expected to develop integrated products— handheld phones or data devices with built-in processors that digitize and encode signals, thereby making them readable only by identical devices. Dutton said GTE expects eventually to transplant some of the technology it develops under the Condor initiative to the commercial market.