Earlier this month, a pigeon with a secret code was found in a chimney in Surrey. The message is made up of 27 codes, each with five numbers and letters. The Daily Mail wrote at the time:

It has been sent to code breakers at Bletchley Park in Buckinghamshire, the intelligence centre where work to crack the Nazi Enigma code shortened the war by years, and to their modern-day counterparts at GCHQ in Cheltenham, Gloucestershire, who also are trying to decipher it.

But in the past month, no one has been able to crack the code. The New York Times writes:

Britain’s code-breakers acknowledged on Friday that an encrypted handwritten message from World War II, found on the leg of a long-dead carrier pigeon in a household chimney in southern England, has thwarted all their efforts to decode it since it was sent to them last month.

And they might never be able to crack it, they say. The Times again:

“The sorts of code that were constructed during operations were designed only to be able to be read by the senders and the recipients,” a historian at GCHQ told the British Broadcasting Corporation. “Unless we get rather more idea than we have about who sent this message and who it was sent to, we are not going to be able to find out what the underlying code was,” said the historian, who was identified only as Tony under GCHQ’s secrecy protocols.

Of course, their inability to crack it has some people wondering if they’re simply lying, and the message is sensitive. The man who found it, David Martin, thinks that they already have deciphered the note, and have decided that its contents are too important and too secretive to release. Others suggest that perhaps they simply don’t care about this code as much as they care about other, ongoing projects. The Times, cheekily, writes:

There was some indication on Friday, though, that GCHQ was not taking 40TW194’s code as seriously as, say, tracking satellite phone communications between militants in the Hindu Kush. One of the most “helpful” ideas about the code, according to Tony, the GCHQ historian, had come from an unidentified member of the public who suggested that, with Christmas looming and thoughts turning, in the West at least, to a red-robed, white-bearded, reindeer-drawn bearer of gifts skilled at accessing homes through their chimneys, the first two words of the message might be “Dear Santa.”

So, either World War II code writers were really good or the GCHQ isn’t as excited about the news a long-dead pigeon carried as about more current secrets.

More from Smithsonian.com:

Top Secret WWII Message Found In Surrey Chimney

Closing the Pigeon Gap