“The Blitz Ciphers” were, according to their (rather reticent) owner, found by a relative of his just after WWII. They were discovered in wooden boxes concealed in the wall of an East London cellar that German bombing had exposed: the ciphers were first described in this December 2011 post on Cipher Mysteries, where they were given their name (though they appear to predate the 1940s by some considerable time).
Eight images (each at roughly 4MP resolution) have so far been released, though it is believed that the complete set is significantly larger. Note that the numbering below is mine (based roughly on order of appearance on the web).
As far as I know, the Blitz Ciphers have not yet been physically examined or analysed by specialist historians: they appear to be on hand-made paper, but no watermark has yet been determined. The text itself has at least one correction and appears to have been written by at least two different hands in apparently quite different inks – most notably, a larger, bolder ‘presentation hand’ and a small, finer ‘annotation hand’, which includes some underlining. Many parts of the writing are now badly faded.
The pages we have contain a number of unusual geometric diagrams, resembling annotated tiles or mathematical ‘trees’, which do not seem to have obvious analogues in other old documents. Another page has a large, well-structured table, with many internal regularities but also no obvious explanation or analogue.
If this artefact is not a modern hoax, it seems reasonably likely to me that it is a document created and held by a secret society, along much the same lines as the recently-decrypted ‘Copiale Cipher’, which turned out to relate to a secret “Oculist” society in Germany. Having said that, all kinds of other possibilities remain in play, so it is too early to say one way or another.
The text seems not to be a simple substitution cipher (because it employs roughly fifty different glyphs), nor a conventional polyalphabetic cipher (because the instance frequency counts have a ‘peakier’, non-flat distribution).
However, if it is a ciphertext, the underlying cipher system could very well be some homebrewed combination of:-
* homophonic cipher (using multiple glyphs for a single character)
* nomenclature cipher (using specialised glyphs for common words, such as “and”, “the”, etc.)
* nulls (using glyphs with no meaning to disrupt cryptanalysis)
Here is my (provisional) transcription key (click on the image to open up a much larger version):-
Here is a (provisional) transcription of part of the text using this transcription key:-