🚀 go-pugleaf

gjb@fig.citib.com (Greg Brail) writes:

[... deleted ...]

: So -- as I've come to expect from Hollywood, most of the technical
: details in the book (and I assume the movie), are either impractical,
: impossible, or nonexistent. (There are a few neat tricks shown, however.)
: But let's assume someone does figure out how to trivially factor very
: large numbers. I understand that would defeat RSA. Am I correct? 

Yes.  The decryption key is trivially obtainable from the factors of
the public modulus.

: How about DES? 

No.  DES does not use problems in number theory.

: Are other common government and commercial cryptosystems based on
: large primes? I assume that one-time pads would still be quite effective.

Certainly.  Some cryptosystems (e.g. the proposed NIST signature
standard) are based on the discrete logarithm problem, which is
generally thought to be of similar difficulty to factoring large
primes.  It is possible that any breakthrough in number theory which
broke RSA could also be used to perform discrete log.

One time pads will always be effective.

: And how about this "Russian codes are different" stuff? Any truth to this?

No idea.

: I understand one can buy source code for DES and RSA on the streets of
: Leningrad (according to Communications of the ACM).

Source code is available by anonymous FTP.  Anyone with anonymous FTP
access in Leningrad could pick it up for free.  Papers discussing
efficient algorithms are freely available worldwide.

: Someday someone will produce a computer-cracking scene in a movie that
: looks as if the people involved have logged in to a system via a modem
: at least once in their lives. I don't think "Sneakers" will be it.
: 
: 				greg
: 
: P.S. If no one agrees that the technical details in this movie are silly,
: I'd be glad to post more.

I agree, it's silly.   Please, no more!  :-)

Andrew.

P.S.  Aren't the actors in the movie a little old to be hackers?