ERNIE — the fastest random number generator in the west

It’s had five lives. It’s considered by many to be the ‘son’ of the World War II code-breaking computer, Colossus. And it’s still the force behind one of the UK’s monthly lotteries. Meet the Electronic Random Number Indicator Equipment – or ERNIE, for short.

This extremely clever piece of kit was first developed by a Bletchley Park code breaker at the Post Office Research Station in 1956. A hybrid between a vacuum neon tube and a transistor machine, it generated random digits from thermal noise, making it ideal to pick the winning numbers for the Premium Bonds. ERNIE 1 had an impressively long life from 1957 to 1972 – and though its latest successor, ERNIE 5, uses much more advanced quantum technology to drum up the numbers, the original idea is still very much the same.

Though its cultural and technological importance are in no doubt, ERNIE’s IP origins are a little harder to pin down. We think we can trace its beginnings to a patent application filed by Abel + Imray in 1947 for an intriguing-sounding invention dubbed, “Improvements in or Relating to the Production of a Series of Random Numbers”. Geoffrey Timms, one of the patent’s applicants, is very possibly the same Geoffrey Timms who worked alongside the great Alan Turing at Bletchley Park.