With the ongoing second World War, Lamarr was inspired to contribute to the war effort by designing a jam-proof radio guidance system for torpedoes. With the help of composer George Antheil, they drafted designs for a new frequency-hopping spread-spectrum technology that they later patented. Lamarr and Antheil realized that radio-controlled torpedoes, which could be important in the naval war, could easily be jammed, thereby causing the torpedo to go off course. With the knowledge she had gained about torpedoes from her first husband, and using a method similar to the way piano rolls work, they designed a frequency-hopping system that would continually change the radio signals sent to the torpedo. Their invention was granted a patent on 11 August 1942. Yet, it was technologically difficult to implement, and the U.S. Navy was not receptive to considering inventions coming from outside the military at the time. Only in 1962, at the time of the Cuban missile crisis, did an updated version of their design appear on Navy ships. The design is one of the important elements behind today's spread-spectrum communication technology, such as CDMA, Wi-Fi networks and Bluetooth technology.