Did you know that the sultry actress from the 1940's, Hedy Lamarr, invented RFID, or radio frequency identification technology, one of the hottest technologies today?

Neither did I, until I heard a speaker state so in a presentation last week.

RFID uses radio frequency signals to track people and transactions — it's the basis for the EZ Pass automatic toll payment system used on American turnpikes, among many other uses. Radio frequency is also used in many keyless entry systems, anti-shoplifting systems, livestock tracking, pet tagging, and inventory tracking.

At first I was a little skeptical that a 1940's movie star had invented this important technology that has suddenly become wildly popular.

So I googled "Hedy Lamarr radio frequency." To my amazement I found that her invention has been written up all over the Internet.

Hedy Lamarr was definitely ahead of her time. In addition to making soft porn in the 1930's before it was fashionable, she even beat Winona Ryder to the punch and became the first major actress arrested for shoplifting, back in the 1960's.

But, we're getting ahead of ourselves. Jump back to the 1940's. Hedy Lamarr and a gentleman by the name of George Antheil patented an idea for "frequency hopping." Frequency hopping solved a problem relating to the use of radio control to operate torpedos. If a single radio frequency were used, then the signal could be jammed by the enemy. Hedy and George came up with the idea of randomly changing the radio frequency to prevent jamming.

Their invention was based upon player piano rolls — which probably explains why their invention wasn't taken seriously at first.

One of the more colorful accounts of Hedy Lamarr's life and her invention can be found at this Britney Spears site (I kid you not!).

But was it really RFID that she invented? Not exactly — it was spread spectrum, a very important related wireless technology. As the Electronic Frontier Foundation noted in 1997 when it honored Hedy Lamarr:

"In 1942 Lamarr, once named the 'most beautiful woman in the world' and Antheil, dubbed 'the bad boy of music' patented the concept of 'frequency-hopping' that is now the basis for the spread spectrum radio systems used in the products of over 40 companies manufacturing items ranging from cell phones to wireless networking systems."

This post was adapted from one that appeared on the author's RFID Weblog.