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Schneier on SecurityA blog covering security and security technology. « Friday Squid Blogging: Giant PVC Squid | Main | Nasty Samsung Phone Exploit » December 17, 2012Possible Decryption of World War II Pigeon MessageA Canadian claims that the message is based on a WWII codebook. A spokesman from GCHQ remains dubious, but says they'll be happy to look at the proposed solution. EDITED TO ADD (1/14): The backstory. Skepticism about the alleged deciphering. Posted on December 17, 2012 at 12:39 PM • 19 Comments To receive these entries once a month by e-mail, sign up for the Crypto-Gram Newsletter. Brython • December 17, 2012 1:06 PM The bits of the "solution" published by the BBC, at least, look extremely dubious, like the guy is just making up sentences whose words each begin with the letters of a group. So apparently CMPNW means "Counter Measures [against] Panzers Not Working", rather than any of the other thousands of sentences with those initials, and Mr Young knows this because he's seen an unrelated code book written before Panzers even existed. Frankly, it's depressing that the press are swallowing this nonsense so uncritically. Dave Walker • December 17, 2012 1:30 PM I'm also sceptical. While tanks were introduced on both sides during WWI, and it appears that German ones were referred to as Panzers back then, I'm not sure the colloquialism "Jerry" was applied to German soldiers until WWII. To my eye, the short, fixed-length letter groupings make me think "one-time pad". Chris S • December 17, 2012 1:47 PM Well, if that was the only evidence, I'd be skeptical, too. However, the Canadian (articles identify him as Gord Young from near Peterborough) claims to have used a code book. In this sense, incidentally, it is maybe better to say the message was "decoded" rather than "decrypted". If he did use a code book, then that piece of physical evidence would go a very long way to validating this claim. pavel • December 17, 2012 1:49 PM It looks exactly like a one-time pad cipher. The guy even considers one of the letter blocks to be six letters, when it's clearly five (The U looks like an LI, I guess, if you're not paying attention.) curious • December 17, 2012 1:57 PM The message itself looks like a code book, 26 blocks of chars for the alfabet + 1 block as possible checkblock, +additional instructions which variation to use (the numbers) ''code'' would come out as FNFJUAREEQYIDDCRQSXR i bet this is too simple though :p emzed • December 17, 2012 2:22 PM So, it’s the alleged decrypter’s contention that it isn’t a code at all, but a clear text transmission composed of abbreviations that all happened to be exactly five characters long? What are the odds of that? A frequency analysis of the letters shows a nearly even distribution –half of the letters in the alphabet appear between 4 and 6 times. Abbreviations would reflect the frequency that the letters start words. Even allowing for a creative military, I’d say there’re too many Js, Ks, Vs, and Zs for this to be plausibly plain-text abbreviations. GCHQ is being far too charitable and the BBC just can’t resist a good story, however absurd. In WWII and afterward, I believe it was common for encrypted messages to be broken into 5-character blocks regardless of word length in order to ease manual decryption. The frequency analysis is consistent with polyalphabetic substitution encryption, such as you get with a one-time pad, Enigma-type machine, or Vigenère cipher. The latter two can be broken, but it’s difficult, to say the least, without a longer text and/or more information about the circumstances of the message (e.g., to do a known plaintext attack). The latter is the kind of kind help the public could provide GCHQ. Evan Harper • December 17, 2012 2:37 PM Sure, it just happens to be written in the cipherer's traditional five-letter groups and to have a uniform letter frequency distribution, but really it's a series of bizarre IM-style nonce abbreviations for semi-grammatical sentences that don't make a great deal of sense in context anyway. Color me convinced. the_pigeon • December 17, 2012 3:21 PM I'm sorry, but the fact that this is getting so much attention is absolutely laughable. This is just a bunch of random nonsensical abbreviations which the author has made up to fit the cipher-text. Bob • December 17, 2012 3:23 PM Looks like a code, vice cypher. Had a laugh at the strained interpretation of the digits at the end. '27' is the group count. My guess on 1525/6 is "station number 1525, message 6", but without more messages, it's impossible to tell. Bob T • December 17, 2012 4:14 PM @emzed Also, he wouldn't say that he knows where the German HQ and Panzers were without saying where they were. Clive Robinson • December 17, 2012 4:38 PM @ emzed, In WWII and afterward, I believe it was common for encrypted messages to be broken into 5 character blocks regardless of word length in order to ease manual decryption No that's not the reason at all. The five charecters result from the use of "commercial codes" to save considerable sums of money back in the late Victorian era (the A.B.C. Tlegraphic code being the most common). Just like diplomatic and military. codes befor them the codes were used to compress sstandard sentences inot "words" (which was the basic chargeable unit). You can read more of the history at, Figureitout • December 17, 2012 5:51 PM It seems odd that Stott died when he was 27, it may have been June 27th, and there are 27 blocks of text; surely just coincidence. I don't understand why a WWI book would be used for WWII, seems a little sloppy for the military. Here's what Mr. Young wrote PM of UK. AOAKN -Artillery Observer At "K" Sector, Normandy. Paeniteo • December 17, 2012 5:52 PM @pavel: "It looks exactly like a one-time pad cipher." You are telling us that you have found a distinguishing attack against one-time-pads just by possibly *looking* at one? ;-) Coo • December 17, 2012 6:34 PM Hey guys I think I cracked the missing groups. WYYNP - Working [with] Yanks Yesterday, No Progress kingsnake • December 18, 2012 7:20 AM I wonder what the Mayans have to say about this. Or Nostradamus. Anyway ... Like Leo Marks, "The Gold Bug" was also the story that got me interested in the subject. (Though in my case I never kept up the childhood passion.) Ivan • December 20, 2012 10:27 PM Nick Pelling of Cipher Mysteries has been following this case. He's filled in a lot of the backstory: http://www.ciphermysteries.com/2012/12/11/... and he too finds the alleged deciphering ridiculous:
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