Okay, can we talk about Alan Turing for a minute? Because every time I think I've wrapped my head around how brilliant this guy was, something new pops up that makes me rethink everything.
Most of us know Turing as the guy who helped crack the Enigma code during World War II — the guy whose story was told in The Imitation Game. But here's the thing: that was just one of his projects. Just one.
Turns out, while he was over at Bletchley Park doing his famous code-breaking work, he was simultaneously working on another top-secret project just a few miles down the road. And this one might actually be the more revolutionary of the two.
Meet Delilah
The story starts with Donald Bayley. Fresh out of university in 1944, young Donald was an electrical engineering graduate who got assigned as an assistant to someone called "Prof" at a place called Hanslope Park. You can probably guess where this is going — yep, "Prof" was Alan Turing.
Bayley's job? Teaching Turing the hands-on practical skills he needed to turn his electrical engineering ideas into real, working hardware. See, Turing was brilliant with the theoretical side of things, but building actual circuits? That wasn't exactly his forte. So Bayley showed him the ropes.
And Bayley took extensive notes. Like, obsessively detailed notes. He documented everything — Turing's thoughts, his experiments, their late-night engineering sessions. These notes would later become known as the Bayley Papers, and they sat in Bayley's possession until his death in 2020.
The Problem Turing Was Trying to Solve
Here's some context: during World War II, encryption was a big deal. The Nazis were using their Enigma machine to scramble written messages, and cracking that became one of the war's most crucial intelligence efforts (thank you, Turing and the team at Bletchley).
But here's what not everyone realizes — voice communication was just as important. Military leaders needed to talk to each other. War room debates happened verbally. Crucial orders were given over telephone lines. And all of that needed to be encrypted too.
The Americans had a system called A-3, but here's the problem — it was basically security theater. Anyone with sophisticated enough equipment could unscramble it. Not great when you're discussing troop movements.
Then there was SIGSALY, developed by Bell Telephone. This thing was impressive — it could convert voice into digital data and encrypt it in a way that actually worked. So impressive, in fact, that it was used by Roosevelt, Churchill, Eisenhower, and MacArthur during the war.
But SIGSALY had one tiny flaw: it was enormous. We're talking about forty racks of equipment, heavy enough that MacArthur needed one installed on a ship that followed him around. Not exactly practical for frontline troops.
Turing's Answer
So what did Alan Turing do? He designed something better.
Drawing on the mathematical insights he'd developed while cracking Enigma, Turing set out to create a voice encryption system that could actually be carried somewhere. Not bolted to the deck of a battleship — but portable. Something a soldier could take into the field.
His design was called Delilah (yes, named after the Biblical figure — Turing apparently had a sense of humor about these things).
Here's the jaw-dropping part: where SIGSALY needed forty massive equipment racks, Turing's Delilah design compressed everything down into just three units, each roughly the size of a shoebox.
The whole system weighed just 39 kilograms, including the power pack. That's small enough to fit in a truck, a trench, or a large backpack. Can you imagine?
Why Does This Matter?
Here's what gets me about this story.
Turing was already working what, sixteen-hour days at Bletchley Park cracking codes? The man would literally bike ten miles each way between Hanslope Park and Bletchley to juggle both projects. Ten miles. On a bike. During wartime.
And while everyone focuses on the Enigma work (which, don't get me wrong, was genuinely world-changing), this Delilah project shows another side of his genius. He wasn't just a mathematician or a cryptographer — he was trying to solve real, practical engineering problems that would keep soldiers' communications secure.
We don't actually know if Delilah was ever fully built or deployed. The Bayley Papers give us the design and the experimentation, but the full story might never be completely clear. Turing died in 1954, and many of his secrets went with him.
But what these papers reveal is that even when we think we know everything about a historical figure, there's always more to discover. Turing wasn't just one thing — he was a polymath who saw connections between fields that most people didn't even realize were related.
And maybe that's the real lesson here. The next time you think you understand someone's capabilities, remember: they might just be running a secret second project you're not aware of.