A coded message found attached to the remains of a hero D-Day carrier pigeon may never be cracked, British top codebreakers have admitted.
Hand-written on a small sheet of paper headed "Pigeon Service," the message was found in a red cylinder still attached to the bird's leg bone.
The pigeon's skeleton emerged in 1982 from the chimney of 17th-century home in Bletchingley, Surrey, when the home's current owner David Martin decided to restore the fireplace.
Unseen for three decades, the message was handed last month to intelligence agents at the GCHQ (Government Communications Headquarters) in the hope it could be deciphered.
But the 27-code cryptographic puzzle has stumped Britain's renowed code-breakers.
The experts had to admit the pigeon may have taken its secret to the grave since the coded message can't be cracked without its codebook.
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"Unfortunately, much of the vital information that would indicate the context of the message is missing," Bletchley Park, a center where, during World War II, top secret codebreaking work was carried out on behalf of the Allies, said in a statement.
Historians believe the bird was dispatched from Nazi-occupied France on June 6 1944, during the D-Day invasions.
Because of Churchill's radio blackout, homing pigeons were taken on the D-Day invasion and released by Allied Forces to inform military generals back on English shores how the operation was going.
The military pigeons were dropped behind enemy lines from bombers, whereupon resistance fighters picked them up, before releasing them homeward bound with top secret messages.
The brave birds played a very active role in World War II (the RAF trained 250,000 birds, forming the National Pigeon Service) and, between 1943 and 1949, 32 were awarded the Dickin Medal, Britain's highest possible decoration for valor given to animals.
The British spy pigeon either got lost, disorientated in bad weather, or was simply exhausted after flying for hundreds of miles. Experts speculate the bird might have attempted to rest on an open chimney, but was overcome by fumes from a fire below and he died.
It is possible the pigeon was destined for the top secret Bletchley Park, which was just 80 miles from Mr. Martin's home. Now a museum, Bletchley Park is where codebreakers worked around the clock to crack the Nazi's "unbreakable" Enigma code.
People from all over the world are now trying to decipher the baffling message.
Sent to "XO2" at 16:45, it reads:
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
Signed "Sjt W Stot," the message features two more codes at the end: NURP.40.TW.194 and NURP.37.OK.76.
GCHQ experts believe that one of them could be the identity of the pigeon in the chimney.
The first group of letters indicated the bird's origin ("NURP" stands for National Union of Racing Pigeons), while the following two-digit number attested its year of registration (40 refers to 1940).The final set of numbers identified the specific pigeon and the area of the country it was from.
Nothing is known of "Sergeant W Stot." The meaning of the message's destination — "X02" — is also cryptic.
"During the war, the methods used to encode messages naturally needed to be as secure as possible and various methods were used," experts at Bletchley Park said.
"The senders would often have specialist codebooks in which each code group of four or five letters had a meaning relevant to a specific operation, allowing much information to be sent in a short message," they added.
The code groups could then themselves be encrypted using a one-time pad. With this system, a random key was used to encrypt only one message.
"The advantage of this system is that, if used correctly, it is unbreakable as long as the key is kept secret. The disadvantage is that both the sending and receiving parties need to have access to the same key, which usually means producing and sharing a large keypad in advance," Bletchley Park said.
The GCHQ experts believe the pigeon's message, which contained 27 codes, each made up of five letters or numbers, was encrypted with the "one-time pad" system.
"This means that without access to the relevant codebooks and details of any additional encryption used, it will remain impossible to decrypt the message," they said.
The only way to crack the code relies in finding one of those WWII codebooks, normally destroyed once no longer in use, and in veteran codebreakers who during the war worked at Bletchley Park or in military signals.
"If 'Sjt Stot' and addressee X02 could be identified, it could give us a better idea of where to look for the information," Bletchley Park said.
Nevertheless, the GCHQ experts believe the message remains "a tribute to the skills of the wartime code-makers."
"Despite working under severe pressure, they devised a code that was undecipherable both then and now," they concluded.
Photo: The cryptic WWII message. Credit: GCHQ .