Walker Spy Ring

The family naval espionage ring that exposed American fleet codes from 1968 to 1985

Overview

The ring led by Navy warrant officer John Walker Jr passed cryptographic keys and manuals that let Soviet intelligence read American fleet communications for most of two decades. Walker recruited his brother Arthur, son Michael, and friend Jerry Whitworth. The ring unraveled in 1985 after a tip from his estranged wife and an FBI sting. Naval damage assessments ranked it among the most harmful breaches of the Cold War. Walker died in federal prison in 2014. The Soviets reportedly built a replica of the American cipher machines to exploit the keys.