[justlurking]

For those that don't recognize this....

The woman on the left is Hedy_Lamarr. The diagram on the left is from US Patent 2,292,387.

Lamarr was a actress with an extensive list of credits.. She was also co-inventor of a system to encrypt radio communications.

The system was not adopted during WWII, but was eventually used by the Navy during the Cuba blockade in 1962.

Why should you care? Look at your cellphone, your Bluetooth headset, and your laptop. WiFi, Bluetooth, and CDMA (used by your cellphone to connect to the nearest tower) are all based on the principles laid out in this patent.

[ETL]

She was one in 2 billion.

[jamaksin]

Or perhaps better known today as spread-spectrum transmission, or just (often random) frequency-hopping.

Instead of using a specific frequency for the entire message, skipping frequencies around randomly makes, for example: (a) jamming harder, (b) RDF cut bearing difficult.

CDMA (Collison Detection - Mutliple Access) is a technique to allow multiple users to share a single communications channel of a network.

Ms. Lararr's patent has nothing to do with encrypting per se.