• Book Extract Overview: Justin Patrick Moore's new book "The Radio Phonics Laboratory" details the secret history of links between wartime cryptography and electro-funk.
• Radio and Telephone in War: By the 1940s, radio and telephone revolutionized communications. In warfare, these signals needed protection. After WWI, substitution devices for secure voice transmission were developed but were easy to break.
• A-3 Scrambler: In 1931, Bell Telephone Laboratories developed the A-3 scrambler used by Roosevelt and Churchill. It divided voice frequency into subbands and used substitution and transposition. But it was eventually compromised by Germans intercepting British prime minister's calls.
• Entering the War and SIGSALY: As the US entered the war, Bell Labs was contracted to create "indestructible speech" with the SIGSALY system. It used a twelve-channel vocoder with ten channels for voice signal power and two for pitch. Vinyl records were used as audio crypto-keys.
• SIGGRUV and Security: The SIGSALY system employed two-turntables and random white noise on vinyl records. The records were made by Muzak Corporation and had a self-destruct mechanism. Synchronizing turntables across the globe was a technical hurdle.
• Complete SIGSALY System: A complete SIGSALY system was heavy with many components and required cooling. It passed Alan Turing's inspection and was used between various locations.
• Special Division and Engineering Firsts: A special division of the Army Signal Corp was set up to operate SIGSALY. Eight engineering "firsts" were achieved in putting the system together.
• Legacy: SIGSALY left a rich inheritance in cryptology and digital communications, still relevant today.