MEIN KAMPF SEITE 5
On Valentine’s Day, 1941, Captain E.M. Drake sent an urgent telegram from Ottawa to London, destined for M.I.8 in the War Office. A “suspicious transmission” had been heard by the Canadians for two days in a row, and Drake felt that it was important enough to get British intelligence involved in the investigation (CDWI00052).
What prompted this urgency was a transmission on the 13th of February with no callsigns. The first part of the message consisted of 221 three-letter groups, each beginning with the letter Q.
Example: QUG QUZ QBB QFB QRA
This was followed by “MITTELSCHWERE GRUPPEN” (in the clear), which could translate to ‘medium/moderate groups,’ and then 180 five-letter groups which were not readable as words (likely encrypted).
Example: XMDJR CBFGW QLAIT RDMZK MANWO
After the probably-enciphered five-letter groups came “KLAR XT AUS MEIN KAMPF SEITE 5 A8” (in the clear), which could mean something along the lines of ‘clear text off of Mein Kampf page 5, paragraph 8’ (if the ‘A’ was short for ‘Absatz’). This was followed by half a page of “plain language in German from Mein Kampf,” Hitler’s infamous manifesto.
Captain Drake did not speculate about the meaning of this suspicious transmission, but this historian believes that there is much more to this intercept than meets the eye.
Q-CODES
In the first instance, the ‘header’ of the message consisted entirely of Q-codes, which are three-letter codes used in radio transmissions to quickly convey the meaning of common sentences, such as QRA, meaning ‘what ship/station are you?’ when sent as a query, and ‘I am [vessel/station]’ when sent as a response. However, in the standard international Q-code, the five examples above are mostly meaningless, and it would never make sense to transmit two-hundred and twenty-one different Q-codes without having any sort of dialogue with another station. Therefore, it is unlikely that the majority of these Q-codes were meant to convey any sort of meaning. It is possible that the Q-coded start of the transmission was nothing more than testing the clarity of the signal.
It is also possible that the 221 Q-codes were a form of obfuscation. There were so many of them, which were for the most part meaningless, that the Canadians would have had a hard time picking out whether or not any of them did have meaning. For example, Drake wrote that the transmission contained no callsigns, but based on a later document from July 1942 (CDWI00313)—in which the U.S. shared with the Canadians all of the German military traffic procedure signals that they had decoded thus far—we know that the Germans also used certain Q-codes as callsigns. Therefore, at the end of the Q-code dump, there could have been a callsign identifying the originator or the address of the recipient, and the Canadians simply did not recognize what looked like international Q-codes as potential callsigns.
Another possible piece of information which could have been slipped into the excess of Q-codes at the beginning of this message is whether or not the enciphered payload of the message (the five-letter groups) was encrypted with the German Lorenz cipher machine. During the war, British codebreakers at Bletchley Park noticed that certain Q-codes, when used by German naval vessels, indicated ‘Tunny’ (Lorenz-encrypted) traffic and told operators how often to change the cipher machine’s key. The codebreakers also observed that transmitting a series of Q-codes was sometimes used by the Germans as a test for whether or not a signal was clear enough to safely transmit enciphered messages (Jack Good, Donald Michie, and Geoffrey Timms, “Part 1: Germany Tunney,” in General Report on Tunny, pp. 13-14. https://www.alanturing.net/turing_archive/archive/index/tunnyreportindex.html).
MITTELSCHWERE GRUPPEN
Moving on to the next part of the message: two words in German followed by 180 unreadable five-letter groups. This historian does not have the requisite knowledge to theorize about what “MITTELSCHWERE GRUPPEN” signifies in this context, but it could have had something to do with instructions for decryption or the use of a cipher machine, based on its position in the message and the fact that it was not itself enciphered. There is also not much that can be said about what is likely the encrypted payload of the intercept—the 180 five-letter groups—when we do not have access to the full text of the intercept.
Using a modern computer, it would be possible to decrypt a longer Lorenz-encrypted message, but not the five-group example Drake provided. Likewise trying to learn more about what kind of cipher was used here by employing statistical methods of cryptanalysis on the five five-letter groups we have would be pointless. We simply do not have enough data to solve this mystery.
However, one interesting aspect of this part of the intercept is that it was exactly 180 x 5 letters long. It is unlikely that a message one needed to transmit would turn out to be such a nice length by coincidence. Possibly the Germans transmitted a ciphertext of set length, no matter the length of the actual message, or they were using ‘padding’ (i.e., nonsense letters added to a message to ensure that there would be exactly five letters in each group). Either of these techniques would have been implemented to thwart codebreakers. In this historian’s opinion, it is not likely that the 180 five-letter groups had no meaning at all in the same way that the Q-codes could have been entirely without meaning.
MEIN KAMPF SEITE 5 A8
Turning now to the final part of the transmission, the recitation from Mein Kampf, there are many possibilities for its significance or lack of significance. The originator may have been an admirer of Adolf Hitler and wished to share their passion for his book with the world via radio. Perhaps it was some kind of attempt at disseminating propaganda across the Atlantic. Or maybe the page, when read out over the airwaves, contained some kind of error—one which a recipient who possessed a copy of the book could detect—which would indicate a key word that could aid in the decryption of a message (possibly the message contained in the broadcast). There could conceivably have been a German agent in the Americas listening to the broadcast.
It is also possible that the page itself was the key to a cipher—a book cipher—where each letter on the page could be matched with a letter in an encrypted message, and thereby used to decrypt some kind of polyalphabetic substitution scheme. However, this option is less likely because there would be no need to read out the page if the intended recipient of the message had a copy of the book, and no cryptographer worth their salt would endorse transmitting the key to a cipher in the clear (not encrypted) over an insecure channel. The ease of using a book cipher is supposed to be that there is no need to exchange a secret key when transmitting messages, because both sender and recipient already have the key (i.e., the book).
More plausible than any of the above is that reading from this book that was so ubiquitous in Nazi Party culture was a convenient way of testing the clarity of the signal, since both sender and recipient would have access to the book itself in order to check for accuracy in the transmission.
Never to be solved?
Unfortunately, we do not have the full text of the intercept from February 13th or any of the text from the intercepted broadcast on February 14th. Having one or both in their entirety would provide more clues to solving this mystery, especially if certain parts of the message changed daily while others stayed the same—perhaps these broadcasts contained daily instructions for changing the key on a cipher machine? Because Captain Drake wrote that the intercepts from the 13th and 14th were “similar” and not identical, we do know that these were two distinct messages. We do not know whether the broadcasts continued after the 14th, however. All we have are Captain Drake’s description of the intercept, and his request to London for “further instructions.”