Lamarr termed the technique "frequency hopping, " a forerunner of the spread-spectrum technology that is used today in communications applications such as Wi-Fi.

WSJ: Book Review: Hedy's Folly

Perhaps make GSM more like CDMA. All the researchers noted that CDMA Networks do not have this problem in part because it uses frequency hopping which makes eavesdropping much harder.

FORBES: Cell Phone Snooping: Cheaper And Easier Than Ever

Both sending and receiving stations would, however, need some mechanism to encode and control the frequency-hopping pattern.

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U.S. Patent No. 2, 292, 387 for a "Secret Communication System" was issued to Hedy Kiesler Markey and George Antheil in 1942. (Markey was the surname of a husband she had divorced in 1940.) The frequency-hopping technology was not put to use in World War II, but it was employed in 1962 during the blockade of Cuba.

WSJ: Book Review: Hedy's Folly