Yes, you read that correctly.
The story is revealed in Richard Rhodes's 2011 book, Hedy's Folly: The Life and Breakthrough Inventions of Hedy Lamarr, the Most Beautiful Woman in the World.
Hedy Kiestler, an assimilated Jew, was married to arms dealer Fritz Mandl, who entertained high-ranking Nazis before the Second World War. Here's part of the Brain Pickings story, which was written by Michelle Legro:
From these dinner parties, she knew about about submarines and wire-guided torpedoes, about the multiple frequencies used to guide bombs. She knew that she had present herself as the glamorous wife of an arms dealer. And she knew that in order to leave her husband, she would have to take a good amount of this information with her.
Once Kiestler, known the world as Lamarr, came to North America, she and composer George Antheil figured out how to create a radio that jumped frequencies.
"A year of phone calls, drawings on envelopes, and fiddling with models on Hedy’s living room floor produced a patent for a radio system that was virtually jam-proof, constantly skipping signals," Legro writes.
Not bad for a woman often characterized as the most beautiful woman in the world.