Anybody seen the news about this pigeon that was found - WWII carrier bird, remains discovered in a chimney, with an enchipered message still attached to its leg - GCHQ boffins unable to break it - they have made a public appeal!
BBC News - WWII pigeon message stumps GCHQ decoders
For my money I don't think it will be broken - sure to be one time or day key based and if there is no record of that or context that may help then its gone - maybe only a pigeon can decipher it?