Re: Anyone seen the 'quantum cryptanalysis' thread?

["Dave Emery" <die@pig.die.com>]

> Duncan Frissel writes

> This differs from the popular view that decryption would eventually win the
> "war" with the encryption and devise a way of defeating *any* possible
> code/cipher.  This "fact" was expressed in Edgar Rice Burroughs' Mars
> stories where he said that the Martians didn't use codes much because they
> were vulnerable.  See also Sneakers in which we have a "black box" decyption
> device that can break any code.  Also the guy who confronted me at the
> London conference last year and said "they broke the satellite movie coding
> system so why can't they break PGP?"
> 
> I wonder where this idea comes from.
> 

	Casually looking at the history of the past 100 years or so of
cryptanalysis, particularly what has been recently revealed recently
about US/British triumphs in World War II, shows a number of startling
successes against what were thought (and even now seem to ordinary
minds) to be intractable ciphers.  It is not very hard to see why
popular mythology, which usually lags the cutting edge of science by at
least several years and even sometimes several decades emphasizes
decryption. After all, decryption seems to have been winning the last
time we were allowed to have a look.

	It is also true that a quirk of human nature that probably
has a lot to do with the origin of religion tends to mythologize to
vast, even epic status those who can do something that ordinary people
can't.  And this hero/god dieification often involves the myth of
unlimited power, which in the case of crypto means the ability to
break any cipher.

	It will take a while before appreciation of the fundemental
revolution represented by number theory based ciphers sinks in.  Even
the simple understanding that there exist unbreakable ciphers right now
that anyone with a floppy disk drive can implement is too advanced to
sink in very far. 

	But probably the worst myth is the notion that most practical crypto
systems were actually intended by their creators to be unbreakable.   

	And of course nobody out there understands that satellite TV
pirates have yet to break any cipher at all (at least as far as I know
as someone who follows this technology).   All the current triumphs have
been based on exploiting holes (mostly involving cloning) in the
key distribution and management in an environment where your enemy
both necessarily has the complete cipher device and several copies
of known to work keys.  

						Dave Emery