Operation “Enigma”: How Military Cryptanalysis Was Born in WWII

October 9, 2025October 17, 2025

Many have seen the fairly interesting, yet still fictional film about how a group of cryptanalysts at Bletchley Park cracked the Enigma code. Operation “Enigma” is one of the most legendary intelligence operations in history.

Yet the Hollywood version of events barely scratches the surface of what really happened during WWII. Obviously, it’s a cinematic work, and they had to compress events and character relationships into a single timeframe.

Those who formed their understanding of historical events purely from the movie believe that the British captured the encryption machine itself, and only thanks to Alan Turing’s genius did they figure out how it worked and how to break the cipher. Let’s just say — that’s an oversimplified conclusion.

The Soviet Analog of Enigma

I personally had the chance to see the Soviet analog of Enigma – Fialka-125M. Every single military unit, including mine, had a “cipher group” where cryptograms were encrypted and decrypted. Back then, coded messages arrived via radio in Morse code. Radio operators would receive them, write down the gibberish, and pass it to the cipher group.

There, someone typed everything on a machine with the current cipher set. The result was a document that went to the unit commander for signature. Most often, based on this coded message, a separate order was issued that interpreted what was said in the encryption. Again, in the Soviet system, the data transmission channel itself was also closed. So what the radio operator received or sent — without even understanding what he was transmitting — got additionally encrypted within the communication channel itself. In other words, if someone intercepted that message, they’d face double encryption.

The Real Story Behind Operation “Enigma”

During World War II, everything worked roughly the same way. However, the transmission channel likely wasn’t encrypted yet. Therefore, the enemy would intercept messages that looked like a set of random symbols — nothing more. All this leads to the fact that Alan Turing’s team and the cryptanalyst himself didn’t actually invent anything from scratch. Several years before them, the Poles captured another copy of Enigma, figured it out, and found a decryption method. Moreover, they used the groundwork from French intelligence.

So the British simply perfected the data processing itself to the point where they could decrypt messages in parallel with the intended recipient. By roughly 1943, the British were decrypting enemy coded messages completely and in real time. Accordingly, from that time on, German command began making more “mistakes,” and the Reich’s armed forces suffered increasingly heavier losses.

The Task Gets Harder: USA vs. JAPAN

The Americans faced a more difficult task. At least because the British and Germans used the same alphabet. Their written symbols generally looked like letters. The Japanese used hieroglyphs. Not only were there more of these characters, but you also had to clearly understand contexts. You needed to grasp what was being discussed and calculate the patterns necessary for correctly decrypting encoded messages. Work on breaking Japanese ciphers — the diplomatic PURPLE and the naval JN-25 — had a long prehistory, but here we’ll simply point to an important, even crucial moment.

It’s believed that a major breakthrough in decrypting the naval code occurred in 1942. At that time, a report from a strike fleet group heading to capture Midway Island was intercepted and decrypted. The Americans knew the fleet group’s composition, timing, and route. Therefore, they built their counter-strategy knowing exactly what the enemy planned to do. In the Battle of Midway, the Japanese lost four aircraft carriers out of four, while the Americans lost one out of three. This battle is considered the turning point in that theater of war. And we’ll only note that, according to contemporaries, at that time American cryptographers managed to decrypt up to 20% of enemy encryptions. However, even that volume of information already provided a significant advantage over the enemy.

Conclusion

We didn’t elaborate on the saga of decrypting messages containing highly classified data without reason. Achieving this goal required time. Accordingly, enormous material, intellectual, and intelligence resources were spent. But both of these cases show how the balance of power and the course of events changed when the British and Americans gained access to secret information.

The success of Operation “Enigma” and the breaking of Japanese naval codes proved one thing: intelligence work can turn the tide of war. When you know what the enemy plans to do, you hold the ultimate advantage.