Cell Phone Security

Cell phones are more vulnerable than regular phones due to two dangers: eavesdroppers can listen in on your calls, and thieves can bill their own calls to your account.

Eavesdropping: Anything you say on an analog cell phone can be easily overheard by someone using a scanner. Digital cell phone transmissions are scrambled for better protection, but eavesdroppers with the right equipment may be able to unscramble them.

The best protection? Be aware of what you discuss on your cell phone. Remember that it acts as a handheld broadcast station. Don't give out your credit card number or other sensitive or confidential information; don't say anything you wouldn't say on broadcast radio or TV.

Fraudulent billing: It is possible for thieves to intercept a cell phone signal and clone the phone's ID numbers (its Electronic Serial Number and Mobile Identification Number, or ESN/MIN). The result is the equivalent of a stolen calling card. Some simple countermeasures include:

• Limit "roaming": Review which phones have roaming enabled and limit these as much as practical. Roaming usually defeats the use of Personal Identification Numbers (PINs). Cloners prefer roaming phones for this reason and they target airport parking lots, airport access roads, and rural interstates. Roaming also makes it more difficult for some cellular carriers to use fraud-detection programs to monitor an account and shut it down when fraud is detected.

• Turn the phone off. Cell phones poll the cellular base station with the strongest signal every few second. This is how the system knows which base station to route calls through. However, this polling exposes the phone to interception and cloning.

• Review all bills and report every erroneous call to the service provider. There are two types of cloning:
  • Outright theft of the phone's ESN/MIN is most common. A bill will reflect hundreds, even thousands of bogus calls.
  • The other type of cloning is called tumbling, where a cloned phone uses a different ESN/MIN for each call. A bill might have only one bogus call this month, none next month, but three calls the month after that. The phone has still been cloned and fraud is occurring.

• Prefer hands-off vehicle-mounted phones to handhelds. The boxes used to capture ESN/MIN have a limited range; cloners will follow an individual they know is using a phone. Recent news reports reflect the chances of an accident increase substantially if a driver is operating a vehicle and a cellular phone simultaneously.