Austrian-born actress Hedwig "Hedy" Lamarr (1913–2000) was the co-inventor of a communications system that she and American composer George Antheil (1900–1959) devised in 1941, during World War II. The invention enabled radio messages to be transmitted without the enemy being able to intercept them—and used the principle on which the technologies of Wi-Fi and Bluetooth are based today. Lamarr was a popular movie star in her day, the Golden Age of Holywood of the 1940s. Her best-known films included Ziegfield Girl, Tortilla Flat and Samson and Delilah.

Frequency hopping

Lamarr and Antheil's invention, the frequency-hopping spread spectrum (FHSS) was intended to stop the enemy from jamming radio-controlled torpedoes by rapidly changing the launch signal from one frequency to another at irregular intervals. The system made use of a piano roll, which supplied 88 different frequencies (one per key on the piano keyboard)—too many for the enemy to scan and jam. Using this system, classified messages could be transmitted without fear of the enemy intercepting any information. The principle was the basis for the modern technologies of Wi-Fi and Bluetooth.