Aussie writer/blogger Pete Bowes has long had an interest in the Somerton Man: so when going through a relative’s WWI war diary recently, he was intrigued to find a cipher:
ILWCO MPAY KOMZ YB2N 2YKM QUOO AVA NJOB BOTG HYJE UT2S VRK PBYN HKP IRCG CR
“What do you make of all that?” he asks.
A good question! As I get older, I find that I appreciate good questions more and more, not entirely unlike the nuances of tasting vintage wine. Compare and contrast this with not-so-good questions (I’m specifically thinking here of “Can you disprove my 200-page cipher theory [attached]?” etc) which tend to leave a lingering metallic aftertaste. :-/
Anyway, I knew almost nothing about British Army ciphers in WWI, so my first stop was David Kahn’s “The Codebreakers” (the full length version) to see if he knew any more. However, Kahn tells us all too briefly:
“The British employed the Playfair with random keysquare. Its use extended even to Lawrence of Arabia”. (p.312)
…and that’s basically it. (In fact, the British Army had used Playfair as a field cipher since the 1890s, first using it in the Boer War.)
So: is this cryptogram a Playfair? Well, you should be immediately able to see a number of things that imply otherwise:
* The apparent presence of “OO” (Playfair almost always replaced doubled letters, e.g. “OO” would get replaced by “OX” or “OQ”)
* The apparent presence of “J” (5×5 Playfairs usually used I and J as the same letter so that the 26 letters of the alphabet would fit into a 5×5 arrangement)
* While most cipher groups’ lengths are even, some are odd (Playfair enciphers pairs of letters)
* The apparent presence of “2” (which might suggest a 6×6 Playfair was used, yet given that this is the only digit, that seems highly unlikely)
Regardless, I ran it through CryptoCrack’s 5×5 and 6×6 Playfair solvers, without making any progress. So it would seem that the cryptanalysis backs up the basic history, which is nice.
But if this wasn’t a Playfair, what was it? Pete Bowes thinks that his aunt’s father was in the Ypres Salient during 1916, and presumably this diary dates from that time: yet all the fancy American trench codes were introduced only in 1918. So I’m a little bit stuck as to what else it might be. The presence of “2” ought to be a tell-tale sign… but of what? I don’t know.
But perhaps you know better? 🙂
Surely the first thing to determine is the accuracy of the transcription. It’s possible the “2”s are “Z”s. Also the group lengths are strange – 5,4,4,4,4,4,3……..It could be arranged as 15 groups of 4 letters, which would be more likely for a cipher.
GeorgeC: I’ll ask Pete Bowes if he would be so kind as to post up a scan, then we can judge for ourselves what the transcription should be. It would also be good if he could narrow down the range of dates within which the cipher was written down, because the British Army seems to have changed its crypto practice a number of times during WWI.
Nick,
It is entirely possible that this is in Playfair albeit a 6×6 Playfair assuming the 2s are actually 2s and not Zs.
My understanding of the Playfair is that the entire plaintext is divided into pairs of letters (with X breaking up doubled letters within a pair) and then enciphered. Individual words are not normally enciphered because so many words have an odd number of letters.
The message consists of 60 letters and when divided into pairs there are no doubled letters. The OO is actually two pairs consisting of UO and OA.
The seeming word division seems artificial. Assuming it is divided into words then the words have lengths of 5,4,4,4,4,4,3,4,4,4,4,3,4,3,4,2 which would make for a rather stilted sentence. Without seeing the actual scan of the message my initial conclusion about word division is that it is a deliberate red herring.
It might however be a code. 60 has common factors of 2, 3 and 5 which means the code groups could be 2, 3, 4 or 5. The trench and divisional codes of WWI in my collection employed code groups of 2, 3 or 4 letters or numbers
A scan of the cipher/code would help immensely but a scan of the entire diary (or at least the several pages around the entry in question) would provide additional context for a possible decipherment.
An additional observation. There are 3 duplicated digraphs, namely KP, OM and YK. If this is Playfair then these duplicates might suggest a crib for decipherment. What are the most frequently appearing digraphs in the English language?
The cipher is only 57 characters long (3 2’s and 54 letters) so that’s hard. The single-letter frequency analysis doesn’t tell us much either. The frequency chart looks monoalphabetic and one is tempted to think it’s just a shift of around 14 because there are some letters missing (D, F, and X), but it doesn’t work that well. The British and the French began using their own trench codes in early 1916, so maybe it is a code. But as far as I know, these were usually three-letter codes. What part of the service was Pete Bowes’ relative in? Infantry? Artillery?
Nick. How it looks. Cipher message .
Battlefield. Belgium. City. Ipres. 1916. Aliance. French Army and British Army. Comander of France. Henry Putz.
ILW. = WILL ( Wall ) substituce 1= A,I,J,Q,Y ).
COMPA (n)Y.
KOMZ. = Room. ( substituce 7= O,Z).
YB2N. = Ybre = Ypres.
2YKM. = 21 – 24. ( substitution Y= 1, K=2,M = 4. )
QUOO. = 16. 00 ( substitution = 6 = U,V,W,X ).
AVA + N = Avan.
JOB. = Job.
BOTG . = Bot (g)H. = Both.
HY. = Hi
JE + V. = Jew.
T2S. = t – 23. ( čas)
U.K. (r) = British army. ( r = 2, Army )
PRYN. = Fran. ( French Army). ( P = F, Y= A) substitution.
HKP. = Henri ( K , fonetic G. ) Gabriel Putz.
IR CG . ? Irsko
CR. = G.B. substitution = (3= C,G,S,L…..2 = B,R,K)
Champallion.
It seems to be a Morse Artillery Code which usually is composed of block of 2 or 3 letters sent by Telegraph.
I’ve posted another, simpler code Percy wrote on Dec 3rd 1916 – it reads like gunnery instructions and might hint back to the earlier cipher.
The importance of the message :
Quit on the battlefild.
Ceasefire 21 to 24 . 12 ( Decembr ).
Hi Jew. ( Meaning : Christmas holidays, the birth of Jesus).
will, company, room, Yper.
company = trops.
room = truce, peace.
Yper = area, city
@Fred Brandes:
“It is entirely possible that this is in Playfair albeit a 6×6 Playfair assuming the 2s are actually 2s and not Zs.”
Possible, yes, but highly unlikely. What are the odds that a mere 60-character message’s ciphertext covers all but 3 of the 26 letters, yet manages to avoid all but one of 10 digits?
@Richard H
The likelihood would depend on the variant of Playfair used, and on how the squares are filled.
if you fill in a 6×6 playfair square with the textbook example of (key phrase) (remainder of the alphabet) (numerals). Sixty characters, three numerals, they’re even all 2’s. Does the fact that I could replicate it on my second try say anything about the war diary cipher though? It might indicate that the Australian contingent was lax in its crypto security during the first year of its first major war. Is that unlikely, given the many historical examples of armies making not taking cryptography as seriously as they should?
Might the code be a word game Percy played when he had the time? I’m beginning to doubt he would have written gunnery codes in his own (miniature) diary on the front line, under fire.
Surely the brass would have distributed specific sheets for such gunnery orders and kept them as a record of battle.
@cf. Nice example.
And you get that distribution because with “textbook” Playfair all the digits (and rare letters like X and Z) end up at the end of the grid,instead of being randomly mixed in. Compare the Kahn quote in the OP ““The British employed the Playfair with random keysquare.” which suggests that some people knew hot to get it right. As you suggest, lax security is all too probable.
I retract my original observation, at least partly: It’s still highly unlikely to be a randomised Playfair, but going on alphabet distribution alone it could well be a keyed “textbook” example, in which case it shouldn’t be too difficult for someone with more patience than me to crack it.
For example if it really is 6×6 Playfair and the grid ends
YZ1234
567890
then those 2’s probably correspond to Ys in the plaintext and there are no actual numbers in the message at all.
OTOH Nick says he’s tried Cryptocrack on it with no success.
Pete: my understanding is that artillery codes were designed as a terse series of operations for the gunners to follow; and also that they
waswere overwhelmingly used in a broadcast-only (i.e. HQ broadcasting out to the field) direction. Which is what makes this cryptogram so interesting, because it doesn’t obviously seem to be that kind of thing (there were no digits in the 1939 British artillery code I found online).Nick, I don’t think it’s a battery cipher at all.
Uncle P is doing something else here.
I’ve posted more images.
The cipher is, ” ILWCO MPAY KOMZ YB2N 2YKM QUOO AVA NJOB BOTG HYDE UT2S VRK PBYN HKP IRCG CR “. The deciphered message that I have came up with is; ” WILBE HOEM TEHC MB2T 2MTH FREE EVE TAEB BETS GMAE RTS2 VUT(?) OBMT GTO WYBS BY “. The message I found is, ” WILL BE HOME MBT2(TRENCH MORTAR BATTERY 2) 2MONTH FREE EVE(EVENING?) ABET BETS GAME RTS2(REMOUNT SPECIAL 2) VUT TOMB GOT WYBS(WEBS?) BY “.
I believe that ” VUT “, might be ” TUV “, or Totally Unmanned Vehicle(UAV), Unmanned Aerial vehicle. These were developed towards end of WWI. There were aerial torpedoes, The Kettering Bug, and an aircraft with no pilot.
Three words for anyone proposing ad-hoc decryptions:
Show. Your. Working.
In other words, state your decryption algorithm up front, before applying it. Also the key.
If the algorithm is more complex than the message or the message is shorter than the unicity distance, what you have is not a solution but confirmation bias: you could come up with a similar “just-so” decryption to make it say anything you like.
My work that I posted uses substitution to decipher the code. The final work is shown as the message that I believe that I have found. You can see by letter substitution what deciphered cipher letter is represented by each corresponding letter in the message that I obtained.
“You can see by letter substitution what deciphered cipher letter is represented by each corresponding letter in the message that I obtained.”
Hmm…
1. Leaving aside the inconsistencies — ciphertext B and C both map to plaintext b; K, N and T all give t; D and J give a; A and E give e; R gives both u and y — what leads you to think that’s the correct substitution? Is there a method? What’s the key?
2 How is the leap from WILBE HOEM TEHC… to “will be home…” not a textbook example of a just-so explanation? What does it even mean?
I will try to show my work and explain. Cipher terms are : ” ILWCO MPAY KOMZ YB2N 2YKM QUOO AVA NJOB BOTG HYDE UT2S VRK PBYN HKP IRCG CR “. My decipher : ” WILBE HOEM TEHC MB2T 2MTH FREE EVE TAEB BETS GMAE RTS2 VUT OBMT GTO WYBS BY ” , or ” WILBE HOME TECH (TECHNICAL?) MB2T 2MTH FREE EVE ABET BETS GAME RTS2 VUT TOMB GOT WYBS BY “. I believe that this could read, ” WILL BE HOME TECH MB2T 2 MONTH FREE EVE ABET BETS GAME RTS2 VUT TOMB GOT WYBS(WEBS?) BY “. ” MB2T ” was abbreviated term for Trench Mortar Battery 2 . ” EVE ” could be Evening . ” RTS2 ” was abbreviated term for Remount Special 2 . I think that ” WILL BE HOME “, means that person or group sending message will be at the physical location of Technical Trench mortar battery 2 for two months and will be free to be contacted in the evenings. I do not see where ” R ” = both ” U’ and ” Y ” in my work. ” A ” in the cipher = ” E ” . For example, ” MPAY ” = ” HOEM “, or ” HOME “.
I enjoy working on ciphers and reading about them. This is what I have derived. However, i am in no way saying that it is 100% correct or the only answer to this enigma. Thanks for sharing your thoughts and ideas about this cipher.
That’s proof by repeated assertion, not explanation.
You have explained neither the mechanism for deciphering nor the key used.
And if the sender meant “will be home for 2 months … free in the evening” or whatever, why not just say so? It’s a shorter message than that ABET BETS gibberish.
As for R = both U and Y: Your “decipher” includes
VRK -> VUT so R -> U, but also CR -> BY, so R -> Y
The real giveaway is this: ” i am in no way saying that it is 100% correct or the only answer”. If it were a convincing decryption, you should be, because the message is long enough (about twice the unicity distance) for a simple substitution cipher to have only one key that yields a coherent plaintext.
So what’s the key?
Key; A=E, B=B, C=B, D=A , E=E , F NOT USED , G=S, H=G, I=W, J=A, K=T, L=I, M=H, N=T, O=E, P=O. Q=F, R=U, S= , T=T, U=R, V=V, W=L, X NOT USED , Y=M, Z=C . Some of the letters in my work represent the same letter. I see the problem that you found about the ” R “, and it should be ” R ” = ” U “, so ” CR ” = ” BU “when using my work.
As far as my statement, ” I … answer “; this is to say that others such as yourself may have a better answer to the enigma than I do. In regard to the rest of my work from ” ABET… BU “, I think that this means , ” ENLARGE OR INCREASE THE LIKELIHOOD OF DOING REMOUNT SPECIAL 2 EXERCISES. VUT (UNMANNED AERIAL VEHICLES) ARE IN A TOMB OR PLACE OF HIDING USING WEBS OF CAMOUFLAGE “.
If you have a better answer please post and show your key and work so I can peruse it.
” BU ” in my work = Bulletin or Communication.
I’m entirely out of my league here, but what is it about Percy’s code / cipher that has you folks beaten?
Can you put a name to it?
Pete: I’m far from beaten, it’s just that these things take time. I’ve put requests in to a couple of Australian museums that seem to have a moderate chance of having an Australian WWI artillery code in their holdings (because, from the context, I think that’s the #1 hypothesis to be testing here). Will post again when I (hopefully) get more details.
Nick: I don’t think there would have been enough time for anyone to code firing instructions. The Salient front was under fire all the time and batteries on both sides were constantly being moved around.
This is another entry in Percy’s diary, and one more likely to have been used in battle.
AS 40 MIN EL
BY ANG 63 Deg RT
3000 2700 FIRE
3600 3300
3300 3000
Cor 150
Conc. 25 min on No 1
1 rnd BY F 3 secs
cor 142 3050
new Tgt
AS 35 nun EL
FZ 106
5 rds GF
Solved .. ?
I received this today from one of the family.
“Ian (Trethewey) has solved the ‘code’ we think.
Part of the diary was lessons he was recording about how
Morse code functions, those lists of letters with a tick beside each row
was him and perhaps others practising Morse too.”
It had to be that simple, didn’t it?
pete: sounds good, but I’d like to see it, all the same. 🙂