Sorry I'm drunk and just talked about decryption but any high quality reading of encryption is just as good. I want get in this very deep.

Look up CTF events related to cryptography.

>>65558234
No.

As someone who knows absolutely nothing about cryptography, would it have been a feasible system to have each uboat have a large book of phrases arranged on a numbered grid, and before setting out on patrol both the uboat and headquarters would be assigned a set of 'displacement keys'? I envision it working along these lines:
>HQ needs to send a message to U-219, which has version #12 of the communications book
>HQ finds the grid square that their intended message is in on
>applies the assigned displacement key, for example: Left 4 columns, down 7 rows
>transmits the displaced message
>U-219 applies the key in reverse, up 7 right 4
>each subsequent communication moves to the next key assigned
I feel like this would either be too clumsy and resource intensive since you'd need to have a massive bank of messages to avoid running into "language" barriers to communicating, but I'm wondering what other issues it would have or if this resembles actual systems used

>>65558204
AES256 is the standard for modern military encryption. If you want to incorporate it into your own projects then there are plenty of open source libraries like cryptlib or OpenSSL that are going to work much better than anything you're likely to write yourself.

You might like this OP:
>https://www.virtualcolossus.co.uk/

>>65558204
some polack did it using math and shiet

Any ASCII compatible encryption machines?

>>65558204
without the machine the work would be a lot harder, but you can't realistically expect to keep the algorithms secret and you mustn't rely on security through obscurity anyway. early enigma was a commercial civilian device.
breaking enigma was really pushing limits of the earliest computers it and if i recall correctly, higher versions with proper use were too hard to break.

>>65558269
first, you can't make a dictionary of all possible messages. at the very least, you need to provide a way to insert numbers, coordinates, dates, place names etc. second, it doesn't seem right to transmit the displaced message - you don't need the whole text to identify the message and the message text doesn't make it easy to actually look it up in the table. you would probably index the messages with numbers or words and send those.
but in the core yeah, encoding messages before encryption is useful if you can handle creation and distribution of the code books

>>65558204
>without a captured device
Germany was selling them to anyone with money before the Nazis took power. That said they did need to capture one to know about the later mods.
>user errors
Impossible to avoid, even without stupid shit like HH if you are reporting the weather on a clear day you have to say clear, if it's raining you have to say rain.

>where does decryption stand now
We might as well discuss the details of 3 stage nukes, the answer is it's extremely classified and all we know is hyperthetically quantum computers could be a problem for some encryption methods.

>reading to get the gist of modern decryption
No idea but there is plenty of open source material on blockchain encryption.

>>65558204
Maybe. The US broke the japanese type 97 diplomatic cipher without access to an actual machine. They deduced from the behavior of the cipher that it used telephone stepping switches instead of rotors, and even figured out enough to have a good idea which particular switch the japanese were using (it was a copy of an AT&T telephone switch) and confirmed after the war that their guess had been correct.

>>65558554
It helped that the Japanese diplomats were particularly retarded. The US would give them a message to send to their government, and they'd encrypt it without any changes, giving the US nice long cribs.

read cryptonomicon op, you won't learn shit but Bobby Shaftoe is a mensch

>>65558557
Lmao is that true?

>>65558455
should have had codewords for weather on different days, like lager on a monday means rain, but lager on a tuesday means clear skies

>>65558455
>Impossible to avoid, even without stupid shit like HH if you are reporting the weather on a clear day you have to say clear, if it's raining you have to say rain.
yeah. i recall that on an occasion the code breakers were missing good cribs, so they asked the navy to mine a specific area in the sea, so that Germans could observe and report it with the known coordinates

>>65558603
it didn't help that the Germans were positive Enigma was impossible to crack.
and British kept their success secret even after the war, because some countries still used descendants of Enigma

>>65558580
yep
Japs had like 20 different encryptions tho for different branches of the millitary so this probably only broke their "diplomatic" cypher

>>65558620
>British kept their success secret even after the war
Funny thing is when they declassified Bletchley Park in the 70s a lot of people that had worked there in the 40s were pissed because they were told to keep it secret forever and had then the government went and blabbed.

>>65558620
>and British kept their success secret even after the war, because some countries still used descendants of Enigma
too bad this didn't help against the soviets

File: Fft356.jpg (11 KB, 300x168)

11 KB JPG

>>65558722
>too bad this didn't help against the soviets
How do you know? Did they tell you "we failed pinky promise"?

>>6555866
I like to think that the infinite number of documentaries on US/UK war ships, planes etc. have taught the chinks a lot. For free, or maybe the price of a DVD.

>>65558847
Philby would have told them about it.

>>65558860
He lost his top clearance in 1951

>>65558204
>What should a noob with mathematical proficiency start reading to get the gist of modern decryption and technology?
As someone else has said, CTFs are not a bad start if you know a bit of programming. Or go on Wikipedia, look up cryptography and jump in the rabbithole, learn about various approaches to symmetric and asymmetric crypto, their mathematical fundamentals, practical applications etc. If you're interested in the currently relevant stuff, read up on AES:
https://en.wikipedia.org/wiki/Advanced_Encryption_Standard
Also if you're in college or have the option of attending some classes (or are just willing to look them up and watch them online), it's a huge part of CompSci and I'd definitely recommend checking it out

>>65558620
>British kept their success secret even after the war
because they were selling them to other (developing/ex-colonial)countries under the guise of them being unbreakable

>>65558639
It broke the first diplomatic cipher. The 2nd and 3rd diplomatic ciphers were broken because they sent out instructions for their replacement ciphers on their previous (broken) ciphers. The Japanese had a very hard time believing that the stupid gaijin could break their superior cryptosystems, even when told outright by informants and spies that their codes had been broken.
All Japanese ciphers - there were dozens of them due to every branch of their government hating each other - were broken during the war. The Japanese continued using many of these long after the war, still believing them to be secure.

>>65558554
Fun facts about the diplomatic cipher.
(a) It used the Latin alphabet, so Japanese had to be transliterated into Engrish in order to use it, and nobody in Japan realized how funny this would be when this came out.
(b) It encrypted vowels and consonants through separate mechanisms
(c) The path for vowels was much less effective
(d) It was possible to detect vowels in the ciphertext

>>65559135
>(b) It encrypted vowels and consonants through separate mechanisms
haha what the fuck
Unrelated though, what was Italian cryptography like during the war? I feel like I've never heard anything about it. Did they just use German supplied Engimas or did they have their own system?

>>65559143
They used their own home-grown variant of Enigma.

>>65558570
>Leprosy

>>65559143
It encoded the alphabet using a variety of pasta shapes

Enigma sold his machines commercially in the 30s, which is how I assume Poland & Britain got a few of them, rather than actually capturing them
But I can't answer your question really, it's been too long since I read up on this
>>65558269
You're describing a one-time pad

>>65558269
The problem i see is that you can see high command issuing a bunch of A1 orders and every unit reacting differently. You probably wouldnt be able to crack what each message meant without the unit's specific seed or codebook, but you could compile a dictionary of all possible orders and extrapolate the most likely plays. Things get worse if you capture any of the grids, because now you know all possible orders issueable by the system

>>65558603
>codewords for weather on different days, like lager on a monday means rain, but lager on a tuesday means
That's just using the same word with additional steps.
It might slow down detection but it's certainly not going to defeat it.
Multiplying the difficult by a fixed single digit constant results in a difficulty that's still in more or less the same order of magnitude, i.e. it scales linearly.
The only changes that matter are those that scale non-linearly.

>>65560252
>The problem i see is that you can see high command issuing a bunch of A1 orders and every unit reacting differently
It also requires the unit and the HQ to both know where the unit is with some precision, in an age before GPS.

File: 1784820407834952.jpg (73 KB, 374x396)

73 KB JPG

>>65559121
>The 2nd and 3rd diplomatic ciphers were broken because they sent out instructions for their replacement ciphers on their previous (broken) ciphers
Jesus fucking CHRIST

>>65560292
Why worry when the smelly gaijin are too stupid to crack our superior cipher folded 1000x? This upgrade is just a precaution because our cowardly spies falsely reported that the straighteyes were reading our messages.

>>65558204
It was used before the war as a commercially available encryption device. The innards were known. Polish cryptanalysts broke Enigma as early as December 1932 and shared their methods with the Allies, enabling British codebreakers at Bletchley Park to read pre-war and early-war Enigma traffic before any machines were captured.

>>65558440
>first, you can't make a dictionary of all possible messages. at the very least, you need to provide a way to insert numbers, coordinates, dates, place names etc
That was my initial assumption of it's limitations
>you would probably index the messages with numbers or words and send those.
True, that makes alot more sense
>>65559285
>You're describing a one-time pad
Ah, that's what it's called
>>65560252
>The problem i see is that you can see high command issuing a bunch of A1 orders and every unit reacting differently.
My presumption that you'd still be able to specify for whom the message is intended for
>you could compile a dictionary of all possible orders and extrapolate the most likely plays
That was my other presumption, if say command asks for a weather report and the next message is similarly spaced from a weather description that would be a giveaway

>>65561100
If you are carrying through plaintext of any kind - even spaces - you're going to have a very very bad war.

>>65558204
Subtitution encription is easily defeated by the simplest AI.

All you need is sodomites. Before furries in IT we had Alan Turing.

>>65558204
>Could they have broken enigma without a captured device
Yes.
>and user errors?
That makes it way harder.

But as others said, Enigma was broken due to the Polish teams having the mathematics down, and Britain investing enough money and time to engineer and build the bombes.

The real weakness was that German U-boats were basically micromanaged, and transmitted WAY too often.

>>65558204
>What should a noob with mathematical proficiency start reading to get the gist of modern decryption and technology?
i'd start with cryptography and learning some terms from wikipedia, to see what exists and what would interest you further. block cipher x stream cipher, symmetric x asymmetric cryptography. various block cipher modes of operation are pretty neat and accessible. various cryptographic hashes, digital signatures, key derivation functions and key exchange algorithms are also closely related. if you wanna dig deeper into the mathematics and computer science, you can check out quantum computers and postquantum cryptography.
to cross into cryptanalysis, look up the various attack models and attacks themselves. you can go through already broken algorithms and how they fell. RC4, MD5, SHA-1. lower SSL versions. the work on breaking larger and larger RSA sizes. every widely used cipher has some cryptanalysis published, usually not breaking it, but breaking some simplified version of it or reducing the work needed to break it

>>65562038
that is a rather simplistic statement. all cryptography substitutes plaintext messages for ciphertext messages

The reflector was the biggest design flaw of the Enigma. Removing that would have made decryption significantly harder. Even with all the bombes and captured equipment they still needed to figure out the combinations for each day and if it took days instead of hours the information was less useful. Adding further rotors and options would make it even harder.
>What should a noob with mathematical proficiency start reading to get the gist of modern decryption and technology?
Look into eliptic curves and Diffie–Hellman.

>>65562113
>The real weakness was that German U-boats were basically micromanaged, and transmitted WAY too often.
Well it worked when wolfpacks worked.

>>65558440
>and you mustn't rely on security through obscurity anyway. early enigma was a commercial civilian device.
Isn't story if enigma is clear example against of "mustn't rely on security through obscurity" rule? Availability and knowledge about enigma design massively easened it's decryption. If design of enigma was kept secret it mostly probably it wouldn't be decrypted until end of the war.

File: typex_mkIII_img3.jpg (186 KB, 1536x1234)

186 KB JPG

>>65563044
The United Nations also used rotor based encryption like Typex but Germany and allies never bothered trying to decrypt them.
Important part of the Polish/British decryption wasn't the commercially available model but a traitor, Hans-Thilo Schmidt, who sold the French secret documents.

Even before code-breaking, the U-boat's greatest nemesis was arguably radio direction finding, made possible by the expansion of HF/DF networks.

>>65561100
>My presumption that you'd still be able to specify for whom the message is intended for
You would either have to call out which unit the information is for in plain text, which is a bad idea, or you'd have to use a universal otp for all your forces to encrypt that information, which is only a small steep away from plain text.

>>65563044
the emphasis is on "rely". sure, it would be a nice bonus to keep it from the allied hands, but the plan is to design a strong encryption that can resist cryptanalysis efforts even with the method known. if you deploy a shitty cipher and try to keep it secret, you've already fucked up and what's left is waiting to find out.

>The Lorenz SZ40, SZ42a, and SZ42b were German rotor stream cipher machines used by the German Army during World War II.
>As with the entirely separate cryptanalysis of the Enigma, it was German operational shortcomings that allowed the initial diagnosis of the system, and a way into decryption.[9]
>Unlike Enigma, no physical machine reached allied hands until the very end of the war in Europe, long after wholesale decryption had been established.[10][11]

>>65563044
>Isn't story if enigma is clear example against of "mustn't rely on security through obscurity" rule? Availability and knowledge about enigma design massively easened it's decryption.
You have that entirely backwards.

Security through Obscurity is a less on not trying to keep your design secret to foil attack but to rely on a strong design in the first place.

>If design of enigma was kept secret it mostly probably it wouldn't be decrypted until end of the war
You cannot rely on the decryption method being secret because it's intended to be used by agents far from your safe territory.
And if you were relying on it being secret, that is literally Security through Obscurity.

You've misunderstood the concept, got it totally backwards, and your poor grammar makes your post almost incoherent anyway.
Also, you mean "broken", not "decrypted", the latter is intended to be performed on every message you encrypt, or you're just writing your memoirs and not sending communication.

>>65563182
>You cannot rely on the decryption method being secret because it's intended to be used by agents far from your safe territory.
There are tiers of safety and information flow about systems possibly captured Good rule of the obscurity hygiene is to not use same system for different level of safety.
For example for spies you probably should use one time pads only.
Then ground forces and small ships.
Then capital ships.
Then headquarters communications.
In the order of rising safety and capability of enemy to capture them.

>>65563212
You have never studied anything about this subject.
Being interested doesn't make you more insightful than anyone who has studied or worked in it.

>>65558204
If I could go back in time and kill one person, it would be Alan Turing.

>>65563347
>You have never studied anything about this subject.
Studying how not to not do things like making commercially available enigma your top secret military enrcyption etc??

>>65563938
No military in WW2 used the original commercial Enigma.

>>65563035
They worked for several periods of time, but the real problem was that their system forced the U-boats to transmit too often, which alowed the Allies to locate them with with HFDF stations, even if the message could not be decrypted.
In many cases, the British couldn't read Enigma traffic in anything close to real time, there was often a lag of several days which might mean that it was too late to warn convoys.

It's also interesting that the Germans knew of the mathematical possibility to attack Enigma. They just thought nobody would go and build the machine to basically brute-force the solution.
Which is kinda dumb, because Zuse had build a series of actual working electromechnaical computers in Germany. The crypto guys probably just didn't know what the compute guys were doing.

>>65563070
Germany did crack British merchant ciphers, and many Soviet ciphers. But I do not know what type of encryption those used.

>>65563973
The Bombe weren't computers, Colossus that was built to break the Lorentz cypher is a better analogy.

>>65563986
Yes, I know. Which is why I specifally called the bombes 'machines' instead of computers.
There is a parallel here to ASICs and general purpose computers.

They knew Enigma could be brute-forced, they just overestimated hwo long it would take.
The user errors (and quite frankly bad procedures and habits) massively helped the Allies, of course.

File: Carbs are literally Hitler.jpg (186 KB, 736x920)

186 KB JPG

>>65559283
Mama mia!

Communications regarding the scheduled rendezvous points between U-boats and supply submarines became prime targets for attack.

>>65558204
>where does decryption stand now with radio and communication signals?
Classic asymmetric crypto is fucked the moment a real quantum computer materialises. The whole world is currently looking into deploying asymmetric cryptography resistant against Shore's algorithm. The EU is working on a legal framework to deprecate affected cryptos around 2033 IIRC. As for symmetric cryptos, quantum computers speed up brute forcing them, but not enough to make a meaningful difference since the algorithm has poor parallel scaling and you can always choose a longer key.

Outside of quantum computers, no publicly know effective attacks exist against correctly implemented modern cryptography. Note, that correctly implemented does a lot of heavy lifting. Fucking yourself over by having mistakes or bugs in your implementation is easy and has happened on multiple occasions.

As for the spooks, no one knows what they are up to except for the spooks themselves, but cracking modern encryption is a very difficult class of mathematical problem to crack so my bet would be on them not having had any major breakthrough.

File: 1762874509068506.png (823 KB, 822x758)

823 KB PNG

>>65559121
>It broke the first diplomatic cipher. The 2nd and 3rd diplomatic ciphers were broken because they sent out instructions for their replacement ciphers on their previous (broken) ciphers

File: Enigma-action.svg.png (274 KB, 1920x2187)

274 KB PNG

>>65564020
The reflector was the biggest weakness and they didn't understand it. They thought that sending the signal twice through the rotors made the encryption twice as good but instead of prevented fixed points and thereby heavily compromised the encryption options.

>>65563938
>Studying how not to not do things like making commercially available enigma your top secret military enrcyption etc??
Now you're just confirming that you are totally ignorant on this subject.
For your sake, I hope you're just pretending to be retarded.

>>65565005
>they didn't understand it
The question here is: Who is 'they'?
The company that made the machines knew. But just because they knew didn't mean the actual users knew.
The Navy ended up buying machines with additional rotors that took months for the Allies to crack despite the bombes being fully functional at that point.

In the end it always comes down to 'the Germans thought it was too hard to crack Enigma, but they were wrong'
The Allies ran a very competent cryptanalysis operation, had first-hand information from the Poles, captured Engima machines, and on top of that built machines that helped in bruteforcing the codes.
German operators were sloppy, whcih often amssively helpewd teh Allies. When it comes to Uboats, German SOP was also dogshit, with WAY too much traffic to and from the boats.

>>65559282
this triggers the shaftoe

>>65565263
Why would you built a machine with a crippling flaw? Cryptoanalysis wasn't that far developed in the 1920s.
If the German allies knew about it, why didn't they tell Germany?

>>65565263
>When it comes to Uboats, German SOP was also dogshit, with WAY too much traffic to and from the boats.
That brings again to the point that you should run separate codes according to different needs of different operations. Uboats require such traffic, also their crypto equipment is inherently prone to a capture (U-boat sinks, enemy raises it, and you can't really even know it happened). So you should isolate that part of your encryption methods and traffic from other areas.

>>65565303
>But just because (((they))) knew didn't mean the actual users knew.
>If the German allies knew about it, why didn't (((they))) tell Germany?
it's a mystery

>>65558234
Capture the flag? This isn't team fortress.

>>65565303
>Why would you built a machine with a crippling flaw?
They understood that Enigma could be broken by brute force - they just calculated that it would take way too long with the mechanical computer available.
If you look at the problem, and see that what you call the 'crippling flaw' is not even relevant because decrypting even a single message would take months or years, why care about the hypothetical ability?
Neither the Polish, not the French, nor the British looked at Enigma and went 'lmao it's useless' like you do with your 20/20 hindsight.
It took years of research, specialized equipment and German user error to actually break into teh code, and it took the capture of several actual Enigmas and code books to truly break it, even with the bombes.

>Cryptoanalysis wasn't that far developed in the 1920s.
You are, quite frankly, wrong.

British and Polish codebreaking was excellent, they read most pre-Engima German codes and almost all Soviet codes, the Germans also read most Soviet and French codes.

>If the German allies knew about it, why didn't they tell Germany?
What German allies? What are you talking about? Italy did not use this system.
The company that built the Enigma knew it could be brute forced. I am repeating myself here:
The German armed forces knew, and didn't really care because they understood decrypting it would take so long that the tactical and operational value to an anemy would be zero.
The reasons why this was not true are listed above, and careless operators made it worse.

>>65565342
>That brings again to the point that you should run separate codes according to different needs of different operations. Uboats require such traffic, also their crypto equipment is inherently prone to a capture (U-boat sinks, enemy raises it, and you can't really even know it happened). So you should isolate that part of your encryption methods and traffic from other areas.
The naval Enigma was physically different from those operated by otehr branches, and the rotors were designed to dissolve in saltwater.

Of course, the Allies managed to capture an intact machine, and the Germans did not know. The German procedures were not secure, and their operators relied WAY too much on their 'unbreakable' Enigma machine.

The fact that the British (and later US) codebreaking efforts were kept secret for decades postwar tells you how important this was for the Allies in teh Atalntic campaign.

>>65565303
>Cryptoanalysis wasn't that far developed in the 1920s.
Lol. LMAO even.

>>65565636
The reflector made breaking it magnitudes easier. Why take the effort of adding additional rotors, the plug board and all the other modifications if they were so convinced of the security?
Italy, Japan and other allies used Enigma derived machine as did their enemies.

>>65565802
>The reflector made breaking it magnitudes easier.
Yes, specifically against the method the Polish-British team used with the bombe. The Germans thought would take far longer then it did, they thought the fact that a letter would never be encrypted as itself would be not important and that the reflector would make it harder.
>Why take the effort of adding additional rotors, the plug board and all the other modifications if they were so convinced of the security?
To get away from the commercial design that was known to literally everyone, to make sure the versions of the branches were different.

In the navy's case, they suspected that something was not working but came to the (wrong) conclusion that it was Allied radar and not HF/DF and Ultra.

>>65566031
>they thought the fact that a letter would never be encrypted as itself would be not important and that the reflector would make it harder.
So why did >>65565263 claim otherwise?

>>65566073
That post says
>Germans thought it was too hard to crack Enigma, but they were wrong
This is pretty much correct.

What exactly do you think is wrong?

>>65566097
He claimed that they were aware of the fix point problem and didn't consider it relevant.

>>65566116
OK, I do not see that claim in the post?
Just that they knew it could be broken but it would take very long.

Which is something I also read. I forgot t he exact numbers but they thought it woudl take months or years to break the code, and the code was only used for one 24 hour period.
Which resulted in claims that it was de-facto unbreakable. Things like the plugboard were added to ensure that all the 'classic' cryptanalytical attacks were impossible.
If they wer aware of the weakness the reflector introduced, I do not know. I also do not know who on the British side found this weakness, or when.

But the Germans sabotaged themselved during the war by formatting all their traffic to start with 'To U-XYZ', ending with 'Heil Hitler', using a preset form for weather reports, and by not using any kind of semi-randomized filler.
Plus a bunch of cases of user error, the Allies capturing intact examples of Enigma, and finally Ultra where the bombes allowed decryption within a day or so.

>>65566476
>OK, I do not see that claim in the post?

>>65565005
>The reflector was the biggest weakness and they didn't understand it.
>>65565263
>The company that made the machines knew.

by the way, if we redesigned the reflector to contain a fixed point (or two fixed points in the simplest case), it would create a stronger cipher, right?

>>65566525
It's not about containing a fixed point, it's about not allowing a fixed point. Each letter has to be mapped to a different letter, thereby significantly reducing the number of possible permutations.
If you get around that it would be harder to crack but it doesn't seem electronically feasible to pass through a rotor at the same point from two different directions.

>>65566476
Why the hell would they encrypt weather reports?

>>65566848
They encryptred everything.
The main problem with the weather reports was that it forced every Uboat to transmit daily, whihc in turn allowed allied HFDF stations to triangulate their positions and movements even if the transmissions were not decyphered..

>>65566586
A solutions would be to have a pair of parallel contacts for each position on all rotors, one 'in' and one 'out', that way you could send the signal from A back to A.

The reflector obviously has to shift the signal from in to out, and vice versa.

>>65563347
>trust the experts
>do you have a degree in this field

>>65566476
>not using any kind of semi-randomized filler.
TURKEY TROTS TO WATER GG FROM CINCPAC ACTION COM THIRD FLEET INFO COMINCH CTF SEVENTY-SEVEN X WHERE IS RPT WHERE IS TASK FORCE THIRTY FOUR RR THE WORLD WONDERS

>>65567814
Probably the most famous example

>>65566848
>Why the hell would they encrypt weather reports?
If you don't encrypt a weather report and you have your own weather reports to compare, you can locate a reporter quite easily.

>>65567434
>do you have a degree in this field
Yes, probably half the people telling that anon that they're retarded have degrees in the field.
Cryptography isn't an obscure discipline, loads of mathematicians and computer scientists study this stuff.

>>65567814
With strong cryptography you don't need the memes at the ends because it's just not feasible to crack it in a reasonable amount of time regardless. That stuff is just intended to confuse people who are looking for shortcuts, which is an admission that there are shortcuts to cracking your crypto.

Why didn't the Uboats just use radio operators from Saxony like the Navajo wind talkers

>>65567955
I understand for submarines on patrol doing weather reports, but for fixed bases? Also, Donitz, due to his care for his men, did more bad than good by sending lots of messages, such as announcing a captain's newborn.

>>65569490
Because Saxons just speak an ugly dialect that's generally understood by German speakers. Bavarian would be a better option.

>>65569533
Germans operated weather stations across the North Atlantic and the British regularly destroyed them.