NSA's Secret Cold War Computer Was a Speed Demon

The NSA had a secret computer system during the Cold War that was faster than any other computer of its time. The machine, called Harvest, was designed and built by IBM for the NSA and ran from 1962 to 1975. It processed intercepted message traffic automatically around the clock and was the engine behind the NSA's most sensitive code-breaking work.

Harvest paired a mainframe with a custom coprocessor that processed data in parallel, making it one of the first machines designed for high-speed analysis of intercepts, ciphers, and codes. It was also one of the first machines built as an add-on to do one job exceptionally well, bolted onto a general computer.

The machine's designers needed to rethink how their system handled information due to its unprecedented processing and storage capacity. They created a customized programming language called Alpha to let code breakers describe cryptographic problems rigorously, similar to scientists using Fortran for data-processing algorithms.