BBC Sherlock Fan Forum - Serving Sherlockians since February 2012 / Does anyone know what CCV1 means in the authorization for Baskerville?

**Posted by Ho Yay** November 1, 2015 3:25 pm

I'm not English and I don't know if CCV1 is an acronym many English people get or it's just random letters.
If it means nothing I thought they might be hints for UMQRA as a cipher, like Ceasar Cipher Variation 1, being "1" a possible key, since this scene is about entering places/mycroft's name literally opens doors etc.

EDIT: maybe it can stand for Credit Card Verification? Can Anyone confirm?

EDIT 2: it seems it might stand for Card Code Verification, which having the word code inside, I'm not sure if this actually supports or not my theory that 1 is a key to a cipher. O.o

Last edited by Ho Yay (November 1, 2015 5:29 pm)

**Posted by Magingus** November 2, 2015 4:58 pm

Looking up the most popular phrases for the acronym "CCV", I would assume it stands for "Card Code Verification" (especially considering the context of the message in the image you posted).

UMQRA is meaningless. It was simply a morse code interpretation of completely random signals.

**Posted by Ho Yay** November 2, 2015 7:01 pm

I'm working on a good theory (here) but I'm trying to see if there is a way the keys Sherlock for Mixed Alphabet and 1 for Caesar Cipher are hinted in the episode.

I'm not sure if the 1 after CCV might mean something.

Last edited by Ho Yay (November 2, 2015 7:02 pm)

**Posted by Magingus** November 2, 2015 7:59 pm

Hmm, interesting. I think you might be looking into this too deeply - but I like the way you're thinking

I whipped up a quick program to automate the cipher from your theory - were you aware that "IOU" produces a real word, as well?

**Posted by Ho Yay** November 2, 2015 9:49 pm

I've looked into IOU as a cipher a bit, but I don't think it is a keyed cipher, because it would be absurd to align I owe you, IOU, a meaningful key and a meaningful plaintext on purpose. Also a three letters word can form very easily and without context there are loads and loads of solutions for IOU. Before thinking this and becoming uninterested I tried some combinations and ASH came almost immediately.
For IOU I had this other theory, but unless the writer casually realized the similarities between IOU and IT IS JOHN in Pitman and decided to use them, it is not something that they could have planned.

I also noticed that with mixed alphabets the word TORCH is close to forming many times, for the way the letters in UMQRA are positioned.
So I thought that maybe I had the right plaintext (since it fits so well in the scene), but the wrong keys and I found the solution coincidentally.
I was working on a program that would give me for UMQRA and TORCH other key combinations for Mixed Alphabet + Caesar or Mixed Alphabet used twice, knowing at least one of the keys, but I was too ambitious and made it check throught all combinations of letters (since keys like SHERLOCK would not be in the vocabulary) so it's too slow and for keys with more than 6 letters it never replies. There is also some bugs probably, the code it's more or less there, but I have yet to test it properly.

Last edited by Ho Yay (November 2, 2015 10:14 pm)