[Cryptography] Cryptonomicon and Solitaire

[Ray Dillinger]

On 12/27/2014 10:34 AM, Dave Horsfall wrote:
> I've just finished reading Stephenson's book (although a few things were 
> left in the air, the discussion of which would be massively OT), and I'm 
> still baffled by Solitaire, despite reading Schneier and critics.
> 
> It seems to be a sort of a self-generated OTP, with some transposition 
> thrown in for good measure; how else could the three-way cut with the 
> jokers be explained, for example?  Bruce himself regards it as strong 
> albeit slow, but to quote Mandy Rice-Davies (deceased, alas), he would say 
> that, wouldn't he...
> 
> Speaking of jokers, I have never seen a deck where the two jokers were 
> *not* the same, and as a kid I used to play those "spot the difference" 
> games (and still do).  Perhaps my eyesight is worse than I thought, so 
> where exactly is this "star"?  Naturally, I don't feel like marking them, 
> but the only brand that seems to be available in Australia is "Queen's 
> Slipper".
> 
> If ever I saw two jokers that were *not* the same, I'd be checking the 
> backs of all cards damned carefully...
> 
> Assume I'm a CompSci/Maths graduate, with an interest in crypto.
> 

First look at
http://www.ciphergoth.org/crypto/solitaire/

for some information about a bias in the output of Solitaire.
I haven't found any indication that someone has leveraged this
into an attack, but it exists.

Moving on from there, pretty much all the card decks sold in the
US support games that call for a "high" joker and a "low" joker,
so the different jokers are not something Stephenson (or Schneier)
just made up.  Different decks do it in various ways - some have
suns on one joker and moons on the other, some are printed color
on one joker and b/w on the other, etc.  So check the backs
carefully because that's always a good idea, not because two
distinguishable jokers indicate that someone is pulling a fast
one.

The most ubiquitous brand sold in the US, "Bicycle" decks from
the United States Playing Card Company, has the same graphic
printed larger on one joker and smaller on the other.

			Bear

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