Despite the technological advances of the past decade, cellular phones remain alarmingly susceptible to eavesdropping. All it takes is a $10 radio scanner to tap into a conversation on even the most expensive mobile phone.
There are a number of scrambling systems on the market today that can cut down on the chances of electronic eavesdropping. But most are prohibitively expensive and offer only limited security for conversations.
That was before PrivaFone Corp. of Baltimore came along with a scrambling system that its maker says offers business users unprecedented security for conversations on cellular phones anywhere in the world.
"This isn't the type of thing that President Bush would use to communicate with Gen. [H. Norman] Schwarzkopf, but it's perfectly acceptable for most business conversations," said Charles Wistar, president of PrivaFone, a joint venture of Baltimore-based Cellular Services Group and Cycom Corp., an engineering company in Portland, Ore.
PrivaFone is a unit the size of a cigarette pack that attaches to any cellular phone. Using a scrambler, the unit makes conversations on the phone virtually impervious to electronic intruders, Mr. Wistar said.
He estimated that it would take a would-be eavesdropper two months using a computer to unscramble a five-minute conversation. The key to PrivaFone's security, he said, is a set of secret algorithms. Using a rolling code, the mathematical security lock changes 20 to 50 times a second.