The Smithy code

27 April 2006

The Smithy Code sounds like a bit of a fun thing; Peter Smith, the judge who pronounced on the Da Vinci Code case has embedded a coded message in his judgement, by setting some of the letters within to be italic. The cyphertext in full is:


(This is what has been on other blogs and forums – I grepped the Google HTML translation of the text to make sure). The capital J almost certainly marks out the beginning of the cyphertext; the letters preceding it are a signifier of the cypher to use, but they could possibly the key. It’s definitely not a shift cypher (I’ve tried all 25 combinations). Justice Smith has dropped several hints – including that methods in the books concerned (The Da Vinci Code and Holy Blood, Holy Grail) have been used – it could be a simple substitution cypher (the phrase is too short for frequency analysis) or a Vigen?re cypher (the fact the pair “mq” appears twice, eight letters apart, is a possible indicator of an eight-letter key? Probably not…). I’ve tried various keywords with a Vigen?re decoder (DAVINCI, LEONARDO etc.) but with little joy. He also mentions “mathematics” – maybe there is a possible link with the Fibonacci sequence here (which features heavily in Brown’s book), but I can’t quite see how.

Not going to spend all night working on this – though as far as I know no-one has cracked it yet (although a Guardian blog commenter claims to have done so, he only gives the plaintext and not the cypher or key, so I’m inclined to believe it’s bollocks). If anyone has any suggestions to make, they’re more than welcome…

2 Responses


It’s a substitution cipher based on the Fibonacci sequence. Solution is here:

Damn! I thought it might be that but then never bothered, as I thought the sequence went above 26 way too quickly. I should have realised that I could have just done the artithmetic mod 26 and it would have been fine. Gr.