International cellular phone

SECURING CELLULAR PHONE CONVERSATIONS: A MATTER OF SCRAMBLING

The recent federal investigation of the controversial cellular phone call between Virginia's Democratic Gov. Douglas Wilder and Democratic Sen. Charles Robb, has brought national attention to the ease by which scanner enthusiasts can monitor cellular phone conversations.

Because cellular is a radio-based technology, it can be monitored by scanners that are readily available at electronic stores. The cellular call between the governor and the senator, which was not monitored by a common scanner but rather by a sophisticated listening device, has wreaked havoc with the 2 politicians' political careers.

Currently, methods are available to privatize cellular phone calls by encryption or scrambling devices that attach to one or both handsets. Several companies, including Transcrypt International and Cycomm Corp., have developed voice privacy units that are installed in the switch and work with scrambling attachments on the cellular handsets.

...Subscribers Are Not Aware of How Easy Calls Can be Monitored

Although cellular operators have been criticized for not informing subscribers of the public nature of the cellular phone conversations, the service providers questioned by MOBILE PHONE NEWS said they do not promise security on cellular phones when signing up customers. In fact, GTE Mobile Communications includes in its literature to new subscribers information indicating that cellular phones can be listened to over the airwaves, Janet Henderson, spokeswoman for GTE Mobilnet, told us.

Recently, GTE Mobilnet added encryption software to its switches in California. GTE's Commando 5000 software, from Transcrypt International, works with a special module that is attached to the telephone cord of the user's cellular phone. A corresponding unit also has been installed in GTE Mobilnet's mobile telephone switching office (MTSO).

Pushing a button on the device automatically scrambles both sides of a conversation from the cellular phone to the MTSO. In the case of a cellular-to-land-line call, the connection then is handed off into the regular telephone system. With cellular-to-cellular calls, it is necessary for both people to have the GTE privacy service for the 2 sides of the conversation to be scrambled.

GTE's service costs roughly 50% more than regular cellular service; the hardware attachment sells for $600. GTE said there has not been a big demand for secure cellular service. "Although sales are good, the secure phone service is not for everyone," said Henderson.

"For the average user, concerned about the immediate privacy of his or her cellular phone conversation, GTE Mobilnet's service is perfect," said Tony Frank, market manager for GTE's Pacific region.

...Current Privacy Equipment Protects Against Scanners

With the Commando 5000, it is virtually impossible for a person with an over-the-counter scanner to listen to a conversation. However, scrambling devices can be compromised. "If a person is so inclined and is willing to spend a great deal of money on sophisticated surveillance-type equipment, that person is going to find a way to listen," said Frank.

Jim Estabrook, spokesman for Cycomm Corp., told MOBILE PHONE NEWS that Cycomm's Privacy product scrambles the transmission through Level 3 security, as opposed to high security, which is Level 4. Level 3 features include: analog voice scrambling techniques; high voice quality; low-(Level 1)-to-medium (Level 3) security; low-cost equipment; and easy operation. However, it is not National Security Agency (NSA) approved.

A secure voice system, which is not offered by cellular operators to the public, would feature voice encryptors for Level 4 for security. The NSA approved equipment for this process which digitizes the voice and encrypts the digital data under a high-level cipher.

Cycomm said there is more demand for privacy services than it originally had anticipated. Toronto-based Bell Cellular Inc. began offering the privacy service in July 1990. McCaw Communications also is involved in providing secure cellular communications. However, the company has not been vocal in promoting this niched service. McCaw has installed the service in several of its Florida markets and several Pacific Northwest markets.

Cellular Services Group Inc., a Baltimore, Md.-based firm, also holds a patent for technology that scrambles cellular calls. The technology, known as PrivaFone, provides the caller with hardware to call any standard telephone in the world and to have radio link privacy without requiring the called party to have special equipment.

...The Advent of Digital Will Aid the Privacy Issue

The advent of digital switching equipment, will inhibit the use of scanners used to listen to cellular calls. In fact, time division multiple access (TDMA) effectively will eliminate the commercial market for scanners used to monitor cellular phone calls, said George Calhoun, senior vice president of marketing for International Mobile Machines Corp. (IMM). "A digital call is a relatively secure call, more secure than a wired phone call," said Calhoun.

The industry's digital standard - - TDMA - - digitizes cellular transmissions and uses voice coding. If dynamic channel selection (DCS) is implemented, the degree of difficulty in tracking the cellular call is increased. The problem today will making private analog calls is that in the scrambling process there is a perceptible degradation of voice quality, said Calhoun.

Digital prevents the average person from eavesdropping. However, the transmission can be intercepted by sophisticated listening devices, said Marsha Bexley of IMM.

Currently, IMM's Ultraphone system, which is similar to cellular, but uses the basic exchange telecommunications radio service (BETERS) frequencies, employs TDMA and is secure from the average person using a scanner. To ensure privacy, the Ultraphone system purchased by the White House had an encryption chip added to the original TDMA system. This prevents foreign governments from breaching security, said Bexley.