As promised a long while back (i.e. before I got caught up in pirate history minutiae, etc), I had some interesting emails from Cheltenham music teacher Allan Gillespie, describing his claimed decryption of Elgar’s well-known Dorabella Cipher.
Allan’s starting point seems to have been my hunch that the Dorabella’s first two words were likely to be “Forli, Malvern”, a modest little seed which he then grew out into his own complete decryption.
Specifically, he claims that it’s a vaguely Vigenère-like polyalphabetic cipher, with the key sequence AIUEGSOLXMKWCQZTDPBNYHFR rotated right by five places every eight plaintext characters, i.e.
AIUEGSOLXMKWCQZTDPBNYHFR - for characters #1 to #8
NYHFRAIUEGSOLXMKWCQZTDPB - for characters #9 to #16
ZTDPBNYHFRAIUEGSOLXMKWCQ - for characters #17 to #24
MKWCQZTDPBNYHFRAIUEGSOLX - for characters #25 to #32
GSOLXMKWCQZTDPBNYHFRAIUE - for characters #33 to #39 (etc)
Furthermore, Allan claims (I think) that the output from this gets mapped onto Elgar’s rotated-3 alphabet via this second table (which he presented in a transposed form to make it look as though the keyword was “HAUNTED” [+Y], but it’s actually no more than a monoalphabetic substitution alphabet):-
... N. NE E. SE S. SW W. NW
u.. A. N. E. Y. T. H. D. U.
uu. G. F. ?. R. M. I. ?. Z.
uuu ?. ?. L. B. S. ?. O. C.(Unplaced letters: K P Q W X)
Undo these two stages (he says) and you get a plaintext of:-
ForlE, Malvern Link
A. and Dai’s qko [=quick opinion?]
Met St Stephen ‘eighty six.
Wed at Brompton Oratory but owed takC Mogul ob’d.
He further believes the Dorabella cipher was “concocted by someone other than Elgar (possibly in the run-up to WWII when GC&CS were recruiting; possibly with Dora Powell’s connivance, more likely not)“.
Having said all that, I should add that I’m not entirely sure how serious Allan is about all this; and, moreover, the likelihood that Elgar would have used a messed-up Vigenère in combination with a second substitution stage seems to me to be as close to zero as makes no odds. But all the same, I’ve tried to reproduce Allan’s claim here as clearly as I can, just in case someone else wants to try to reproduce his results.
As you probably already guessed, I’m almost completely sure (as I indeed wrote to Allan at the time) that this “sits in the esteemed and excellent company of those such as Eric Sims and Tony Gaffney who have tried to solve the Dorabella’s cryptographic mystery rather at the expense of its historical mystery“. That is, neither the details (in the allegedly derived cleartext) nor the methodology (that Allan believes to have been used to encrypt the message) cast any light on Elgar, Dora Penny, their relationship, or any reason that such a devilish complex cipher system and linguistically idiosyncratic message would have been appropriate or even useful.
Allan response was that by replying in this way, I was (entirely unsurprisingly) acting in the same way that other cipher mystery establishment figures do, by working hard to “resist any attempt by an outsider to knock down [the establishment’s] battlements”.
Gosh darn it, but doesn’t it just turn out he’s got me bang to rights there? I indeed spend three nights a week chairing a secret cryptographic cabal downstairs at the Athenaeum Club library (or, failing that, Westminster School’s dining hall next to the Abbey) that decides how to misdirect plucky independent codebreakers away from the heretical and uneasy truths behind cipher mysteries. This website is, of course, simply part of our community outreach programme: and let’s face it, when the obfuscating powers of the NSA, GCHQ, and the Bilderberg Group get combined in this way, what chance do all you ordinary people stand, hmmm?