After Weeks of Trying, UK Cryptographers Fail To Crack WWII Code 263
An anonymous reader writes "A dead pigeon discovered a few weeks ago in a UK chimney may be able to provide new answers to the secrets of World War II. Unfortunately, British cryptographers at the country's Government Communications Headquarters (GCHQ) have been unable to crack the code encrypting a message the bird was tasked with sending and say they are confident it cannot be decoded 'without access to the original cryptographic material.'"
No surprise there (Score:5, Insightful)
Given that the original message looks supiciously like it was encoded with a one time pad, it's really not at all surprising that they can't crack it without the relevant pad. Which was probably destroyed a long time ago.
Re:No surprise there (Score:4, Funny)
Which was probably destroyed a long time ago.
Which is, some time after destroying the one-time pet?
Easy! (Score:5, Funny)
Wenn ist das Nunstück git und Slotermeyer? Ja! Beiherhund das Oder die Flipperwaldt gersput!
Re:Easy! (Score:5, Funny)
Wenn ist das Nunstück git und Slotermeyer? Ja! Beiherhund das Oder die Flipperwaldt gersput!
HHAHAHAHAHAHAHAHAHAHAHAHA!
*dies*
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...looks supiciously like it was encoded with a one time pad
Exactly. One time pad encryption the most secure. Unless they can track down the encrypting agent, he's (she's) still alive, and lucid enough to speak, its not happening. Or they find a code book with that day's pad in it, in a long forgotten room or something.
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Given that the original message looks supiciously like it was encoded with a one time pad, it's really not at all surprising that they can't crack it without the relevant pad. Which was probably destroyed a long time ago.
I'm curious: how do you tell by the looks of a cyphertext that it was encrypted with a one-time pad? Yeah, it's written in groups of five characters, and makes no (obvious) sense...but that is no clue as to the method used to encrypt the text. Breaking up words into equal groups is done (obviously) to obfuscate word boundaries, it's not a practice restricted to one-time pads.
Re: encoded with a one time pad (Score:3)
... and in this case, sent with a one time pigeon
Re:No surprise there (Score:5, Informative)
[ citation needed ]
Here, let me help you.
citation [wikipedia.org]
So unless you classify the key as a "clue" (rather than a cluebat) you need to rethink that.
Re:No surprise there (Score:5, Funny)
It's not ROT13 (Score:2)
Grandparent is getting OTP mixed up with ROT13. I do that all the time. It cost me my job once.
I tested that. I even ran it twice, just to make sure.
Re:It's not ROT13 (Score:5, Funny)
What did you run twice? The XOR one time pad or the ROT-13?
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Aw, but according to the TV all anybody needs is a few hours, perhaps a larger computer than usual if it is "military grade" encryption, and a gui front end in VB, and you can decode ANYTHING!
Re:No surprise there (Score:5, Insightful)
Your citation is incomplete. Key reuse is one way to weaken the encoding without forking over the key itself, though this needs multiple messages encoded with the same key.
If you've re-used a key, you're no longer using a one time pad. (Hint: Why do you think it's called a one time pad? [emphasis mine])
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Your citation is incomplete. Key reuse is one way to weaken the encoding without forking over the key itself, though this needs multiple messages encoded with the same key.
If you've re-used a key, you're no longer using a one time pad. (Hint: Why do you think it's called a one time pad? [emphasis mine])
Venona was supposed to be an OTP and it was cracked by the reuse of the pad.
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I don't think you have even the remotest idea what Venona was.
It was the code used by the atomic spies. Alexander Fomin (nee Feklisov) was the agent in charge of the ring. Klaus Prigsheim a faculty member at KU was the host when he talked in IIRC 1960. Arthur Schlesinger Jr. was his debate counterpart. Fomin sounded a lot like Bela Lugosi.
Several point out that it is not a OneTime Pad if you reuse the pad. The pad was reused because of the workload, and the code was broken. Fomin said that Ethel Rosenberg was not involved.
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Re:No surprise there (Score:4, Informative)
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Re:No surprise there (Score:5, Insightful)
Please re-read the entire cited text. Pay special attention to "never reused in whole or part"
(also, even a single re-use can completely compromise all other messages that used a given pad, if the plaintext of a single message encoded with that pad is discovered by other means)
I'm not a cryptoanalyst, but I play one on TV
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If I recall correctly, you can recover the key simply by compareing the two encrypted messages. You don't even need the plaintext.
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From the GP's quote:
"never reused in whole or part"
I know reading comprehension isn't among the best of a typical Slashdotter's abilities, but really? It's not a one time pad if it's used more than once, is it?
Re:No surprise there (Score:4, Insightful)
In which case, YOU AREN'T USING A ONE-TIME PAD! It's called "one-time" for a reason, you know.
Re:No surprise there (Score:5, Interesting)
Well, that's a matter of semantics. If you implement a large-scale, properly-designed one-time pad system, but then a pair of lazy and/or ignorant code clerks re-uses individual OTP sheets for some of the traffic between them (contrary to orders and training, of course), then do we say "it's not a one-time pad system", or that "it's a misused one-time pad system"? Either statement might be arguably valid.
Or maybe all of your code clerks properly use each sheet once and then immediately destroy it, but the factory that produced the keying materials messed up and included duplicate sheets mixed into some of the books, resulting in compromise of the system. Which has actually happened, by the way [wikipedia.org]. You might say that it wasn't actually an OTP system, or you might say it was an OTP system in which implementation mistakes were made which compromised some of the traffic. Those mistakes may have been unintentional errors or deliberate acts by undercover agents to weaken the system, but the folks who designed and oversaw the system intended to deploy a proper OTP system and thought that they were doing just that.
Or maybe you create an OTP system, distribute good keying material without blunders like repeated pages, but then an undercover agent runs out of keying material, has no way to obtain more, and then must choose between stopping communication, communicating in plaintext, or re-using OTP sheets to get critical information through and hoping that the adversaries don't detect the situation. I lean towards calling this situation "not OTP", but it's still a matter of semantics.
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Deviating of course weakens it. But in practice, this may be irrelevant.
Imagine you're a German code cracker, and your men intercept like 100 messages sent out by the British forces (by shooting those pigeons) that are known to be encrypted using one-time pads and using code words. Maybe two of them have used the same pad: you don't know which ones, nor that this is actually the case.
As one-time pads are known to be uncrackable, you're likely not even going to try.
Re:No surprise there (Score:4, Insightful)
Length isn't even relevant. Proper use of a OTP recommends simply copying the remaining pad past the end of the cleartext, or to a random length beyond it. This makes it impossible to determine the length of the cleartext. The cleartext just ends in a standard End of Message, which can only be identified by the recipient with the pad key. "We will attack at dawn. End of Message." could be transmitted as a two page block of ciphertext. It's not a waste since the pad cannot be reused in whole or in part anyway. That entire page of pad just gets torn out of the book and burned when the message is sent.
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Your statement demonstrates a fundamental misunderstanding of the one-time pad. One-time pads are not like other forms of encryption, they are simply modular arithmetic with a set of random charact
Re:No surprise there (Score:4, Insightful)
You're right. If you know what the decoded message is, you can easily decode it without knowing the pad.
Otherwise, you have no chance if the pad was correctly created and used, as any character in the message can decode to any other character.
Re: No surprise there (Score:2)
I think you still don't get it: with OTP there's no way to tell appart "we must attack" from "I'll miss you.".
Re: No surprise there (Score:5, Interesting)
A clue does not help you a bit. The only thing you can get out of a OTP is the maximum length of the message, but not the minimum or actual length,. Everything else is completely arbitrary and depends completely on the key. You can literally decode all possible messages with that maximum length out of that encrypted sequence with the right key. All Twitter posts ever written, all messages passed around in WWII, a whole bunch of Haiku's and what ever else you want you can get out of that sequence with the right key. That encoded sequence is essentially just random junk without the original key. The only clue that brings you to the original message is the original key used to decrypt it.
Re: No surprise there (Score:4, Insightful)
Your point can only be this: the set of messages that might reasonably have been sent can be guessed as the deciphered text. The actual encrypted data gives you zero information on that if the OTP was used properly.
Re:No surprise there (Score:5, Insightful)
While that is true, you will note that i said probable content. Yes there are any number of equally valid decodings. However few will make sense in the context in which they were sent.
The assertion that there are any number of possible decodings only works when you have zero knowledge of expected content, and as such its a tired and juvenile objection.
It's not that there are "any number of equally valid decodings", but there is every possible decoding. If the word "APPLE" is encypted with a one-time pad into "XYZZY", there are potential one-time pads that will decrypt that string into "APPLE", "IPHONE", "STEVE", "WINMO", "GOOGL", "ANDRD", "SBRIN", "LPAGE", "BILLG", etc.
How do you know which of those is the "valid decoding"? How does your knowledge of expected content help you?
Re:No surprise there (Score:5, Insightful)
He's right, you clearly don't understand how one time pads work.
With a properly used one time pad, ANY message (of the same length) is equally valid. Typically you salt the message with some nonsense or whitespaces too, so any message of length = the length of the encrypted message is possible.
So you can make up any message you want, gibberish or real words, and you have no idea if it's the real message or not. You cannot use frequency analysis, dictionary attacks, content hints, or anything else against a properly used one time pad.
You're thinking of simpler encryption algorithms that DON'T use completely random pads. Things like Enigma. If you know something of the content of the message that can help immensely in decrypting those messages, but again, prior knowledge, guesses or whatever have no effect on the security of a properly used OTP.
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Wow, I don't witness that particular brand of cluelessness very often on slashdot.
With a one-time pad there *are* any number of possible decoding. The key is the same length as the clear text. This means that you have *literally* no way of knowing that you have successfully decoded it without knowing the clear text or the pad.
Re:No surprise there (Score:4, Informative)
That's a codebook, not a one time pad. They are distinctly different. Code books are theoretically crackable given sufficient ciphertext and a model for the plaintext (e.g. English). In practice "sufficient" ciphertext is never going to happen. One time pads are uncrackable in theory. In practice mistakes can be made that make them not true one time pads and thus potentially crackable (but that require multiple messages using the same pad -- not the case here).
Re:No surprise there (Score:4, Informative)
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If the pad was used more than once or used repeatedly over the message, then there might be hints to decode it.
You mean one-time-pad-recycling? Like in environmentally friendly Soviet Russia . . .
http://en.wikipedia.org/wiki/Venona [wikipedia.org]
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One time pads are not impossible to crack, provided you have some clues about detecting a successful decoding
Not generally true (assuming a genuinely random one-time pad). In order to decrypt anything, and know you have arrived at the original plaintext, not some arbitrary plaintext, the plaintext needs more bits of redundancy than the length of the key; otherwise multiple possible keys will yield "probable content" when tried.
Because the key for a one-time pad is longer than the message itself, you're going to get every possible "probable content" as a candidate, because there's a one-time pad that will "decrypt
Re:No surprise there (Score:5, Insightful)
You still don't get it.
You might know that the message is 'The Commies have XXX tanks' where XXX is a number, but if the pad is correctly generated and used, the XXX can decode to any three digit number whatsoever, so that knowledge gives you no information at all.
Re:No surprise there (Score:5, Informative)
But as stated elsewhere, messages are not random, so the laboratory exercise does not represent the real world.
When you send a spy in to determine the number of tanks crossing a certain bridge, you don't consider an order for lamb chops and left hand threded eels to be a proper decoding.
Yes, but you don't understand the fundamental problem of your argument. With an OTP, the sentence "0 tanks crossed" is just as likely as the following:
"2 tanks crossed"
"3 tanks crossed"
"4 tanks crossed"
[...]
"144 tanks cross"
"346 tanks cross"
And so on and so forth. You can only run a reasonability analysis, if any of those above was less reasonable than the others. So not only would you need to know that there is a spy and that the spy counted tanks (instead of, say, planes or flowerpots), you would also need to know the exact number he counted and that the spy has not counted wrong. You'd also need to know how he phrased the answer.
In short: You'd need to already know the decoded message to say which decoded message is correct. The reason is very simple: In a One-Time-Pad, the key and message are completely interchangeable. Given only the encrypted text, it is just as hard to find the key as it is to find the original message. This is the ideal property all encryption methods strive for.
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You can discount gibberish and orders for lamb chops if you are quite confident that the message was, for example, English text, and that "lamb chops" was not a code phrase for something like "crates of ammunition". But you still can't distinguish between "FOURTEENTH TANK BRIGADE WILL ATTACK ON NOVEMBER TWELFTH" vs. "EIGTH INFANTRY BRIGADE RETREATING WITH HEAVY CASUALTIES". In any case, code words, code phrases, abbreviations, jargon and spelling errors can all be reasonably expected in legitimate military
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It doesn't matter that the message isn't random, the *key* is random, and never reused. While the message (most likely) not something nonsensical, it could be *anything* that *does* make sense, as well. You can't narrow it down to something that makes sense or something that doesn't make sense. You can't narrow it down at all.
Re:No surprise there (Score:5, Informative)
Given a ciphertext N characters long, there exists a one-time pad that will decrypt that ciphertext to ANY clear text message. So if you have an N-length bit of ciphertext (as it appears these chaps do) and you brute force it and decode an N-length string that 'looks' correct (e.g. "The fleet has launched") that's just great...the problem is that THAT clear text is equally likely to be the correct clear text as any other string of text that long, including all perfectly-structured sentences, with correct pronunciation, containing jargon...in all languages...that long. And if they are salting and/or stuffing the clear text, you don't even have the length as a clue.
Re:No surprise there (Score:4, Insightful)
The reason one-time-pads cannot be broken is fairly non-intuitive, but it's worth understanding. You should understand that it is beyond pointless to even attempt to brute-force a one-time-pad transmission, because you know before you even begin wasting CPU cycles that you WILL find EVERY N-length message that can exist, and you will have no reason to favor any of them. That's why you don't even try. You jump right to trying known/broken ciphers, frequency analysis, looking for possible misapplications of the one-time-pad technique, or something else, because brute-forcing one-time-pad transmissions mathematically cannot work. It's not that it doesn't work, or that it's too hard, but it mathematically is beyond being possible for it to work.
Comment removed (Score:5, Interesting)
Re:No surprise there (Score:5, Funny)
That last batch activated my copy of Windows XP.
Re:No surprise there (Score:4, Insightful)
One-time pads are impossible to crack, in the sense that all messages are equally likely. Think about this for a moment. You can think of many plaintexts of that length. Each one could be the result of a different pad. Since those pads are equally likely, the plaintexts are also equally likely.
We do have the message length, and we also have some information in cleartext (e.g. the time it was sent and who sent it). That's it.
There are weaknesses in an OTP system, but they are typically due to poor key management.
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Re:No surprise there (Score:5, Funny)
Messages small enough to be carried by pigeon were most likely necessarily small
So you're saying that this message was quite literally a "tweet".
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One Time Pads are indeed impossible to crack, if the pad is indeed used only one time, and is indeed fully random. That's because it makes any message that's the same length as or shorter than the ciphertext equally likely.
If I sent you the ciphertext PDXS, how would you know if it decoded to "EAST", "WEST", or any other four letter word?
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One time pads *are* impossible to crack, by the very definition. With a one-time pad, there's no "partial" decoding whatsoever, no attack vector, no weakness. Any method that you apply that result in a structured sentence would be pure random chance. In fact, you can apply any random "pad" to the cipher to obtain anything, from a grocery list to rocket schematics.
One-time pad (Score:3)
Having "some clues about detecting a successful decoding" doesn't help with a (correctly-used) one-time pad. Every message of the correct length can encode to the same cyphertext, for some one-time pad, so in the absence of the pad the cyphertext contains no information at all about the message except its length.
Just to be quite clear about this: you say "[a] decoding that renders a perfectly structured sentence with proper spelling, and/or recognized jargon could be picked out by computer as a "highly pro
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Exactly.
One time pads are not impossible to crack, provided you have some clues about detecting a successful decoding.
For any plaintext message of the same length you can construct a pad. This makes the cipher impossible to break. One pad will yield "attack at dawn", another "hello kitty". For any message there is a pad. A brute-force iteration of all possible pads will only yield all possible messages. The only angle of attack is to see how the pad might have been created in the first place (like seeds and sequences used) and attempt to reconstruct it.
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It probably would have helped if they had used the right letters. In the last line, it should be GQIRW. The writer's F's were shaped entirely different (as evident in the second line).
AOAKN HVPKD FNFJW YIDDC
RQXSR DJHFP GOVFN MIAPX
PABUZ WYYNP CMPNW HJRZH
NLXKG MEMKK ONOIB AKEEQ
WAOTA RBQRH DJOFM TPZEH
LKXGH RGGHT JRZCQ FNKTQ
KLDTS FQIRW AOAKN 27 1525/6
Re:No surprise there (Score:5, Interesting)
Nope..
it is possible to "decrypt" out of the ciphertext any message whatsoever with the same number of characters, simply by using a different key, and there is no information in the ciphertext which will allow [the reader] to choose among the various possible readings of the ciphertext.
Got that from this . It's an interesting read. In a message encrypted by a one time pad, even two letters right next to each other may not represent the same letter in the original plaintext.. [slashdot.org]
Re:No surprise there (Score:5, Informative)
even two letters right next to each other may not represent the same letter in the original plaintext..
Any cipher worth its salt will have this characteristic.
A one time pad is a mixing operation; a combination of random data with the plaintext being protected, using an operation that preserves entropy; which means that none of the randomless from the one time pad bits are lost EVEN though the plain message being encrypted is non-random, the result will have exactly as much randomness as the more random of the two bits being mixed, and therefore it is mathematically impossible to discover the value of a single bit of plaintext, without knowing the corresponding bit of one time pad.
Nor is it possible to determine the value of any single bit of one time pad, without knowing the corresponding plaintext bit.
Any attack requires discovering the value of the one time pad through an outside source, or exploiting a weakness in the pad, such as key reuse, OR inadequate random number generator used to produce the pad.
The only thing you can ascertain about the one time pad by looking at the enciphered message, is its maximum potential length, since you can see the number of symbols that are printed on the card, and that will be a finite number.
Re:No surprise there (Score:5, Interesting)
Re:No surprise there (Score:4, Interesting)
Actually I read something interesting ...
By 'something interesting' you must mean Neal Stephenson's Cryptonomicon. I agree, it is quite an interesting book. One of my favorites in fact.
Re:No surprise there (Score:4, Insightful)
As another aside, one of the weaknesses of the Enigma Cipher was that the subsitution wheels never substituted one letter with the same letter. This fact turned out to be somewhat helpful in breaking the cipher...
Many early ciphers had weaknesses that were the result of not fully understanding the loss of randomness from seemingly logical "optimizations".
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Actually, it was even worse than that. The same physical wires were used both for "input" and "output".
Let me try to explain. Each rotor was a short cylinder with 26 contacts on each end. Inside the wheel were wires which connected the pads on one end with the pads on the other end. Typically, these were not the same pads. So applying a voltage to a pad on one side would make the voltage appear on some corresponding pad on the other side. This effectively implemented a permutation of the alphabet.
The machin
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The people running the program understood this stuff at least as well as you. The girls picking out the balls would have been working with exceptionally clear and inflexible rules.
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Any cipher worth its salt will have this characteristic.
I see what you did there.
Weeks (Score:2)
Should give it some time before one calls it quits.
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Re:Weeks (Score:5, Informative)
You would seem to miss the point. Here's a message encrypted with a one-time pad: WXYZ. Want to brute-force it? OK, try all the permutations of four letters that can exist in the OTP (36^4 of them, if the pad accommodates English letters and digits). Spoiler alert: One of those permutations will yield LOVE. Another will yield HATE. Which one is the correct message?
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...One of those permutations will yield LOVE. Another will yield HATE. Which one is the correct message?
Considering this is /. probably: NERD
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WXYZ = The Detroit radio station where The Lone Ranger got his start.
In case that's a clue.
Cracked! (Score:4, Funny)
I just installed windows XP using the first row.
The answer (Score:2)
Eggs, Milk, Cheese, Bell Peppers, Ham and Onions... ...it's the recipe for my typical omlette!!
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Ah, but in the UK, they're called "sweet peppers" or just "peppers". Maybe it's a duress code?
Be sure to drink (Score:2)
OVOMALTINE!
http://www.ovomaltine.com/ [ovomaltine.com]
BTW light wheat malt, fresh milk and fresh chocolate syrup is tastier but not as convienient. For an improved taste use sprouted wheat flour ala diastatic malt. This is the only ahref=http://www.ehow.com/how_4620081_sprouted-wheat-flour-diastatic-malt.htmlrel=url2html-22218 [slashdot.org]http://www.ehow.com/how_4620081_sprouted-wheat-flour-diastatic-malt.html> place I could find it.
Yes it is on topic if you know history. ;)
Done (Score:2)
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Shouldn't someone do a "Hitler Rants" subtitled clip for this already?
It probably said: (Score:2)
Maybe it was a fake... (Score:2)
... a joke someone intentionally left... it can't be crecked because its not encrypted.
Its worse than that. (Score:5, Interesting)
My Aunt was a radio communication specialist in the channel islands where they communicated with the underground and later the anti Nazis within the third reich. My Dad was involved in counter espionage within Great Britton. They were both recruited by the Canadian military and then trained by the combined British and Canadian military intelligence division long before the US joined in.
Not only was key info done with one time cipher it also used specialist language. For instance the word pie after decryption might be construed to be to mean supplies. Only the individuals who were taught the language could decode it and no more than a few individual agents sending info from within Germany or France used the same code specific language.
If the pigeon corpse was from D Day then it would have been really early in the landing. As the beach head was secured the code receiving specialist people moved in to undisclosed places in Normandy. Are they absolutely certain the pigeon was from D Day? If not it may have been from other sources as my aunt told me there was some underground agents using them before 1944...Some even in the Dieppe region!
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The message was sent to GCHQ in Cheltnam to decode, GCHQ is what replaced the Government Code and Cipher School which was based at Bletchley Park and had 2 tasks: 1) keep our communications secure using codes and ciphers and 2) break AXIS codes and ciphers. People focus on the second one but the first is also important and we were very good at both parts. Now they kept copies of the code books like you describe (our bomber crews replaced them regularly and were charged with burning their copies if they cra
The Next Step. (Score:3)
In the UK, in our authoritarian wisdom, we made it illegal not to provide passwords or decryption to encrypted material.
GCHQ are now well within their rights to arrest the pigeon to learn it's secrets.
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GCHQ are now well within their rights to arrest the pigeon to learn it's secrets.
http://xkcd.com/538/ [xkcd.com]
Looks like we've found an edge case where that might not work. I'm not putting it past them trying though.
What if that is the one time pad? (Score:5, Interesting)
What if that is not an encrypted message, but the encryption key for a message?
I am not a cryptography expert, but I suppose there would be no way to discern the two right?
If it is the key and not a message, than no amount of decryption effort would matter.
END COMMUNICATION
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Have the tried India? (Score:2)
lets name the algorithm... (Score:2)
Thinking in reverse (Score:2)
Is there a possibility of that being the one time pad?
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Re:lol (Score:5, Funny)
Really, Mr. Ballmer, you need to take some anger management classes.
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The bits of government responsible for creating and maintaining cyphers are different to the bits of government that use them; the problem is generally with the end users.
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WWII had codes we can't crack but governments today are routinely hacked and their passwords dumped in pastebin?
Only because things have to be decrypted at some point. The cryptographic primitives (symmetric encryption, public/private encryption, hashes, MACs etc.) don't change much and have been pretty much rock solid. People still use RSA as invented in the 1970s, except with longer keys. I don't recall any mainstream symmetric cipher being broken either, DES had too short keys (56 bits) but you still have to brute force it. If all you have is an encrypted message you'll get nowhere in 2012 with RSA/AES, you'd get
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For all we know 4 or 5 pigeons were released, each with only every 4th or 5th letter of the text, all encoded differently.
With that kind of packet loss even three letter agencies would be at a loss
...and this might only be the "CheckSum" pigeon...
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For all we know 4 or 5 pigeons were released, each with only every 4th or 5th letter of the text, all encoded differently. With that kind of packet loss even three letter agencies would be at a loss
Actually, I'm pretty sure there were two copies of the message sent. I deduce this because of the arabic numeral "2" entered on the form field titled "Number of copies sent". Also, there's the identifier codes for two pigeons on the message. Or didn't you look at the pretty picture in TFA?
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...a now probably destroyed code book designed specifically for a single operation or mission...
Perhaps it is possible that the MOD still has a backup of the book/pad. While a field agent would tear off and destroy one-time pad pages, the HQ would retain the original.
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You could design a single-use code that isn't a random pad, such as assigning meanings to sequences of letters, in essence making a set of "words" for that mission. For example, "CQ" might mean "soldiers", "TQ" might mean tanks, etc. Notice in the ciphertext, the triad JRZ is repeated twice and the first and last 5 characters are the same.
That said, spot checking a few letters, it appears the distribution is pretty flat, suggesting an OTP. If you strike the last 5 letters (assume they're a repeat of the
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