Decoding a Carrier Pigeon
by Joseph B. Zekany
Discovery - 0x1
In 2012, David Martin found a long dead pigeon in the chimney of a 17th century house in the village of Bletchingley, south of London. Attached to the leg bone was a small canister containing an encoded message. The message was sent to the British GCHQ agency to see if they could break the code. As of this writing, the agency has not cracked the code, but they have made copies available on the Internet for any would-be code breakers.
GCHQ Analysis - 0x2
Agency specialists think the message is from the allied D-Day landing in Normandy, France on June 6, 1944.
The pigeon may have been flying home from British units in France when the bird died. The GCHQ has said deciphering the message will require a codebook, and possibly used a one-time pad encryption system. A one-time pad is a system where a message is encoded one time with the sending key. The sending key is then destroyed. In this case, the message was sent by carrier pigeon. If the pigeon was captured, the only information the enemy would get is a jumble of words, and the pigeon isn't talking. If the key pad was captured, the enemy would not be able to decrypt other messages, because both keys are destroyed aid never used again.
The cipher text reads:
AOAKN HVPKD FNFJU YIDDC RQXSR DJHFP GOVFN MIAPX PABUZ WYYNP CMPNW HJRZH NLXKG MEMKK ONOIB AKEEQ UAOTA RBQRH DJOFM TPZEH LKXGH RGGHT JRZCQ FNKTQ KLDTS GQIRU AOAKN 27 1525/6The form indicates that two copies of the message were sent. Additional notations, in a color different from the code groups and signature, are NURP 40 TW 194 and NURP 37 OK 76. These identify the specific birds used. NURP stands for "National Union of Racing Pigeons." The pigeon whose remains were found is apparently 40 TW 194.
The sender signed his name W Stot Sjt. The agency says this is an old fashioned abbreviation for sergeant, and links the message to a British army unit.
The destination for the message was X02. The agency said the date box on the message was left blank.
My Analysis - 0x3
The encoded message consists of 27 five letter code groups. At the end of the code groups is a string of numbers: 27 1525/6
Is it possible Sgt. Stot put the date at the end of code groups? 1525 is military time for 3:25 pm.
Is it possible he used key 6?
I also notice that one code group was used twice. The code group AOAKN is used once at the beginning and once at the end.
Is it possible X02 means Executive Office II or Executive Operations II?
I also found that two copies of the message were sent. If this is the case, and the message made it back to HQ, then its contents were more than likely written in a combat report somewhere.
Historical Fact - 0x4
At the time of the D-Day invasion in Normandy, France, General Bernard L. Montgomery commanded the 21st Army Group.
He had two field armies in Normandy, and an additional division. He commanded five armored brigades that were under the army group control. In the east was the second army that had 12 combat divisions. They were divided into three British and one Canadian Corp. After the British and Canadians landed on Gold Beach, Juno Beach and Sword Beach, General Montgomery went for the city of Caen and attacked the city with British and Canadian troops, but the offensive was bogged down by German Army Group B. Once Montgomery's forces had taken Caen, Montgomery implemented his planned offensive south of Caen. The operation was called Goodwood.
Operation Goodwood was to be launched in coordination with General Omar Bradley's Operation Cobra. Goodwood was a major offensive by the British second army to push out from Caen and began on July 18, 1944, but had not gone well.
Decode History - 0x5
It's here I put forth my theory about the encoded message, based on the information provided by the GCHQ press release, my analysis, and the historical facts surrounding the month of July 1944 in Normandy, France. The historical record will provide the context for cracking this coded message.
I started with the code group AOAKN.
Being a British military message, I reasoned the message was some kind of combat report, so AOAKN could stand for REPORT.
Following that line of thought, it's not a big jump in logic to think that GQIRU stood for END.
This is because AOAKN started and ended the 27 code groups. Now I only had 24 code groups left to solve.
At the end of the 27 code groups was the string of numbers: 27 1525/6
I hypothesized that 27 was the date, and 1525 was the time. 3:25 pm is at the end of the day. Knowing pigeons roost at night, 3:25 pm would be a good time to send the pigeon across the English Channel.
If you were Sgt. Stot, what information would you want to send HQ on the evening of July 27? How about the status of the current operation?
From the historical record of July 18 to July 30, 1944, we know that General Montgomery was executing Operation Goodwood. We also know it wasn't going well. We know General Montgomery then had General Demsey launch the II Canadian Corps in Operation Spring on July 25, 1944.
Sgt. Stot was limited by how much information he could send by pigeon, so he had to be to the point in his report. He could have informed HQ in five words about the status of Goodwood.
I hypothesized that HVPKD stood for OPERATION, FNFJU stood for GOOD, YIDDC stood for WOOD, RQXSR stood for HAS, and DJHFP stood for STALLED.
You may have noticed I split the words GOOD and WOOD. I believe HQ would never put a compound code word into a one-time pad. If the pad was captured, HQ wouldn't want to give the enemy any intelligence about any operation in the past or future.
Moving on, we are left with 19 code groups.
What other type of information would Sgt. Stot want to send HQ? Could he have wanted to tell HQ what kind of resistance the British and Canadian troops were up against? On the first day of the operation, the British second army lost 270 tanks and 1500 men.
On the second day, the British second army lost 131 tanks and 1100 men. In two days, the second army lost 2600 men. That number is absolutely sobering.
Again, I hypothesized that POVFN stood for HAVE, MIAPX stood for ENCOUNTERED, PABUZ stood for HEAVY, WYYNP stood for ARTILLERY, and CMPNW stood for FIRE. I believe the number of lost men backs this up.
We're down to 14 code groups.
Would it be reasonable to think Sgt. Stot wanted to send HQ the position of the enemy?
Working with this thought, I reasoned HJRZH stood for LOCATED, NLXKG stood for ENEMY, MEMKK stood for TROOPS, and ONOIB stood for POSITION. He might want to convey maneuvering information, as well as plans for who the second army should attack.
With this in mind, we can solve the rest of the code.
AKEEQ stood for IMPORTANT, UAOTA stood for SECOND, RBQRH stood for ARMY, DJOFM stood for FLANK, TPZEH stood for SOUTH.
The last code groups will tell us who the target was.
LKXGH stood for AND, RGGHT stood for ENGAGE, JRZCQ stood for PANZER, FNKTQ stood for GROUP, KLDTS stood for WEST.
So the decrypt looks like:
REPORT: OPERATION GOODWOOD HAS STALLED. HAVE ENCOUNTERED HEAVY ARTILLERY FIRE. LOCATED ENEMY TROOP POSITION. IMPORTANT SECOND ARMY FLANK SOUTH AND ENGAGE PANZER GROUP WEST. END REPORT |
At the end of the coded message were two strings:
NURP 40 TW 194 NURP 37 OK 76 |
The curators at the pigeon museum at Bletchley Park believe these are the pigeon's identity numbers.
What if these numbers are combat map positions? TW could stand for Tiger Wehrmacht and OK could be Oberkommandos. Remember, in 1944 the British military didn't have GPS. I checked the latitude and longitude for Caen. Not even close: 49° 10' 53"N / 00° 21' 49'W
I've seen old military maps. They are broken into sectors by a grid. They have numbers around the borders. This is called the map index. These numbers are used to locate positions on the map. I believe 40 TW 194 and 37 OK 76 are the enemy's positions.
I asked a person who served in the military if they still used maps like this. The answer was yes.
I quickly wrote 40 TW 194 and 37 OK 76 on a piece of paper and had them look at it. The answer was, "Yeah, just like that, but I don't know what TW stands for."
I told them it was from World War II, and that it might stand for Tiger Wehrmacht. The answer was "That sounds right."
I was then told "Once you find a position, you put a one to five mile square around the position, with the target at the center of the box." This is called a kill box. They said once you've done this, you call in fire on that position. Based on the answers, I reasoned NURP stood for TARGET.
Conclusion - 0x6
Many may ask why we should care about a message sent so many years ago.
I say because Sgt. Stot may have given his life to send this message. It's possible this message could have saved lives had the pigeon made it back to HQ. I would really like to know if Mr. Stot survived the war. I hope so, but if not, I think the world should know of his service.
Now pour a pint and raise a toast to Sgt. Stot. You are not forgotten, and we thank you for your service.