15 or so years ago our local historical library had a code breaking challenge - it had all sorts of classic ciphers including that the polyalphabetic substitution one similar to Enigma's. And the texts themselves were mostly your mama jokes in Yoda speak (because the librarians are assholes) and I can't describe the deflating feeling of spending a good couple of hours or so to decrypt YO MAMA SO FAT.
this post was submitted on 09 Oct 2025
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The HH at the end didn’t necessarily help crack the code, it was a trick that could be tried once in a while to see if the radio agent on the other end had been compromised. “Heil Hitler” was such an automatic response for German radio operators that they would sometimes automatically “HH” if one was sent to them and they were faking being an allied agent.
Regarding WW2 and cryptography, I Highly recommend Between Silk and Cyanide by Leo Marks. Well written, easy read, dry British humor, and a real view into the British cryptography development, deployment of agents behind enemy lines, and the price that was paid. Can’t recommend it enough.
Except that the signoff with the same phrase every time was made up to dramatize the movie. They did often have predictable messages, like including the time & a weather report, which allowed crib dragging to work by guessing which of a few possibilities had been transmitted.
It was a Swiss invention. The Nazis only bought the exclusive rights.
Nah. Known plaintext wouldn't help cracking a good encryption scheme. Enigma was not a great encryption scheme. It had a few fatal flaws.
When i first heard of this praxis, i though that "wow, how stupid must they be to not make a rule about signing off with the same phrase".
In reality this was probably part of some poor engineers recommended instruction, which was promptly ignored because of pavlovian conditioning. Or ignorance by those in charge of making the messages.
Can't teach stupid.
Oh it was, AFAIK they were supposed to switch some settings regularly, but didn't, so they used the same keys way more often than they were supposed.
It's the 1940s version of ignoring IT instructions about phishing emails
“Easy”
Like 4 countries had to work on it.
And invention of a new computer that was much faster than anything else at the time.
The Bombe machines used to decipher Enigma are usually described as being electro-mechanical devices. Perhaps you could argue they were special-purpose computers of a sort, but definitely not the programmable, general-purpose machines most people think of when they hear the word "computer".
The first programmable electronic computer was developed at Bletchley Park, but it wasn't used to decipher Enigma.
Even without the sign off, from what I remember from the movie (so take it with a grain of salt), they reported the time and weather every morning. That’s formulaic enough to make it a little easier too.
Yeah, isn't the thing about the sign-off a dramatization? They sure did repeat certain words like OKW and BdU, as well as sending uniform weather reports and changing their settings too infrequently. But that bit sounds fabricated.
Exaggerated, but not fabricated. There were common sign offs, and messages like "nothing to report" that were seen often. Another example is an officer who started every message with the same long formal greeting when messaging their commander. The most common was messages starting with "to " (in German and written for transmission, so "ANX" was the actual plaintext).
The timing of that weather report was also crucial, as the code changed daily. Getting that report in the morning allowed them to crack the code, and then use that to decode messages for the rest of the day.
We're clean on opsec
Similar story.
The US Air Force designs the SR-71 Blackbird to be the ultimate spy plane. It's meant to be undetectable and untraceable.
Some general demands they paint USAF in big letters on the side.
More like the F-117 Nighthawk getting shot down whilst bombing Yoguslavia because the flight path became too predictable
TIL
The SR-71 wasn't all that stealthy. Its main defense was that it moved too high for flak and too fast for SAMs. It was retired when interception capabilities improved to match it.
It was at least partially retired because some Asshat General decided that since the USAF has multi role attack airframes, that we didn't need recon aircraft anymore. As far as I can tell the only viable threat to the planes were SAAB Viggens.
I'm not salty. You're salty.
Eh the use of recon aircraft has been fairly outdated with satellites and remote aircraft
the problem with sattelites is that they have to be on a predictable course. any opponent able to reach space can destroy them. the communication to remotely piloted aircraft can also be jammed as part of an attack. it's why they could use an astro-inertial navigation system on the SR-71 that could not be jammed and would allow the pilot to sway from the planned course, but also go back on course. i can't believe they retired it. it closed a gap.
Yeah the NRO satellites really make me doubt that. $2-$6b satellites capable imaging the sunlit side of the planet every 90 minutes would be a stupid expense if any country could just shoot them down.
to shoot one down is expensive and creates space debris, but
a few countries (China, India, Russia, and the United States) have successfully shot down their own satellites to demonstrate their ASAT capabilities in a show of force
Didn't NASA have a couple of them for a while?
Hm, I like the story of the U-2 better, in which Kelly Johnson, the plane's designer, tells the CIA the Soviets won't be able to shoot it down BUT that they are massively ramping up their capabilities and will have caught up by 1960. The plane was eventually shot down on May 1, 1960 to the great embarrassment of president Eisenhower.
Happy May Day, Mr. Krushchev!
That was on purpose, They knew it wouldn't matter, it was never shot down. It's like they built the Titanic in the 80's and decided to name it "200% more unsinkable". Pure hubris
Kinda hard to read something moving at mach 2+ though right?
Fascists are fucking idiots.
I wouldn't rely on that.
You mean the group that supposedly had the "superior people" and the "superior army", yet couldn't win the single war they started, aren't massive morons?
They are history biggest losers at least.
You are talking about Nazis, OP is talking about Fascists.
I thought this was mainly because they intercepted the same message which was sent twice
It's slightly "way more complicated". They occasionally forgot to update the key settings between messages, resent identical messages with different keys or encryption systems, or just chose easy to guess keys.
There was also a defect in enigma where no letters could be encoded as themselves. This meant that you could use knowledge of what was likely in a message at a certain location to rule out keys, since any letters in common disqualified the guess.
That’s a brilliant description, thank you
I believe that was Lorenz, not enigma. The higher level code. Basically Hitler and his generals only.
An operator missed a letter in a message. He then reset the machine and re-encrypted it. 2 almost identical messages like that were enough to figure out how the encryption operated. They didn't see a physical Lorenz machine till after the war.
Read that the guy cracking it had like a mental breakdown because it was so complicated.
The sheer pressure. It should be a crack too small to prise open. However, if you do, all of Hitler's personal messages are up for the reading.
With a slight error somewhere in the middle of the second one. Or so I remember.
And that is why you make sure your encryption algorithm allows for a letter to be one itself after encryption.
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“Thank you for your attention to this matter.”
I really need to watch The Imitation Game.
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