Actress Hedy Lamarr (nee Hedwig) and composer George Antheil received US patent for their "Secret Communications System", an early version of frequency hopping using a piano-roll to switch among 88 frequencies to make radio-guided torpedoes harder for enemies to detect or jam. The U.S. Navy rejected the idea, then seized it as "alien property" in 1942 (Lamarr was Austrian) but filed it away with no record of a working device being produced. via @wikipedia
