One of every 10 Americans now has a cellular telephone. And the number
is growing fast: Every day, 28,000 more are hooked up. 
     First of two parts

     That's 28,000 more people vulnerable to high- tech highway robbery.
     The Cellular Telecommunications Industry Association (CTIA) reports a
total of $482 million in fraud for 1994, or about 3.7% of total industry
revenues, up from $365 million in 1993.
     The industry is adopting new technology in its effort to stay one step
ahead of cellular thieves. You can help, by adopting your own fraud
prevention techniques.
     First, it helps to understand how cellular phones work. With today's
technology, small geographic areas or ''cells'' each have a tower with a
transmitter and receiver. As you drive from one cell to another, your call is
handed over to the next tower and the channel you were on can then be used by
someone else.
     There are three types of cellular phones. Mobile phones are installed in
automobiles and operate off of the car battery. Transportable phones plug
into the cigarette battery in your car or can be taken with you. And small
hand-held portables - the smallest weigh only about four ounces - can fit in
your briefcase or purse and travel wherever you go.
     Every cellular phone has two identification numbers. The manufacturer
installs an electronic serial number, referred to as the ESN, and the carrier
assigns a mobile identification number, or the MIN, similar to the telephone
number on your home phone.
     The ESN is supposed to be fixed and unchangeable. The MIN can change,
since the phone itself could change hands or a customer could move to another
city.
     When an account is activated, the two numbers are paired and stored in
the cellular carrier's computer switch. But the numbers are vulnerable.
     The first massive wave of cellular fraud involved ''tumbling,'' or using
a random series of electronic serial numbers so that calls appeared to be
made by new customers or by customers outside their local calling area. The
industry effectively put a stop to tumbling by moving to pre- call
verification. Now calls do not go through unless both numbers match.
     Today's big problem is ''cloning,'' in which thieves use software to
reprogram stolen numbers into a cellular phone so that the phone, and the
caller, appear legitimate.
     Numbers are easily stolen. Since signals are blocked in underpasses and
most tunnels, and then must be re-sent, criminals often stand on an overpass
or just beyond a tunnel exit to pick up cellular numbers with high-tech
scanning devices. Another popular location, according to Michael Houghton of
CTIA, is outside airport terminals, where arriving passengers frequently turn
on their cellular phones.
     This type of fraud used to be discovered only when a customer complained
about a bill loaded with calls to unfamiliar numbers. Today carriers are
trying to stop cloning before it starts.
     Some carriers are using personal identification numbers, although users
often find it a nuisance to enter another set of digits.
     On another front, less visible to customers, more than a dozen vendors
are developing monitoring systems to be used by cellular carriers. Cellular
Technical Services of Seattle, for example, is marketing software that, in
the words of Cellular's president Bob Dahut, ''puts up a wall between the
thieves and the carrier's cellular system.''

     The system, called Blackbird, uses radio fingerprinting plus other
distinctive characteristics to identify each telephone. When the software is
in use, the carrier's system can shut down a cloned phone as soon as the
caller presses the ''send'' button.
     As the cellular industry moves to digital phones, which will code
conversations into a stream of data bits instead of directly transmitting
voices, new technological forms of authentication will be employed and
numbers will be harder to steal.
     Most of the anti-fraud war, as Houghton puts it, ''is being waged behind
the scenes by the carriers.'' But customers can help by alerting carriers to
anything unusual. CTIA lists the following protective measures you can take
as a cellular customer:

Lock the phone or, if it's removable, take it with you when you leave your
car, even if it's in an attended garage or with a mechanic.

Be careful with your paperwork, which contains your electronic serial
numbers. Don't leave documents in your glove compartment.

If you are in an area where the signal must be re-sent, either coming out of
a tunnel or leaving an airport, wait a few minutes before turning on your
phone. The delay, says Houghton, lets you get away from the area where
thieves might be scanning.

Watch out for unusual activity on your monthly cellular phone bill, and
report suspicious calls to your carrier. (Some carriers are now monitoring
calling patterns and may detect unusual calls before you do.)

If you don't plan to use your cellular phone to make long-distance calls in
general, or international calls in particular, ask your carrier to shut down
this service. ''Call-selling'' operations frequently use counterfeit cellular
phones to provide international calling service to customers throughout North
America.

Don't assume frequent hang-ups or wrong numbers are the result of simple
error on a caller's part. They should be reported to your carrier because
they may indicate that someone else is using your mobile number.

If you become aware of illegal wireless phone activity, you can report it to
CTIA's Fraud Task Force via the Internet. The E-mail address is:
cell-fraud@tmn.com. Tipsters who wish to remain anonymous can type:
an205326@anon.penet.fi.
     Tuesday's News For You will discuss other types of phone fraud,
including ''slamming,'' the unauthorized switching of long-distance services.


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Copyright (c)  1995 Investors Business Daily, All rights reserved.
Investor's Business Daily - Investor's Corner (04/24/95)
Arm Yourself Against The Cellular Bandits
By Grace W. Weinstein


Transmitted: 95-04-21 22:25:08 EDT (aaaa4opv)