Dan Brown - Digital Fortress book

vedaal at hush.com vedaal at hush.com
Thu Jan 15 17:31:12 CET 2009

>Message: 1
>Date: Wed, 14 Jan 2009 11:47:58 -0500
>From: "Robert J. Hansen" <rjh at sixdemonbag.org>
>Subject: Re: Dan Brown - Digital Fortress book

>The TRANSLATR machine does not work and cannot work, not under the 
>laws of physics as we know them to be.


as well as the inaccurate crypto of the 'uncrackable' cipher,

but it does raise a fascinating question:

"assuming a brute force attack is feasible in real time,
how could one design a cipher that is invulnerable to  brute force 
(other than an OTP )?"

as a general possibility:

(1) [as explained in the Digital Fortress book]
what if the decryption program didn't know when it had successfully 
decrypted ...

(a) change the ciphertext, and let the brute force machine merrily 
try to crack the wrong ciphertext ...
(re-encrypt the ciphertext with another random session key,
then if the brute force attack tries all possible ciphertexts to 
find which one is the right one,
it sort-of becomes similar to attacking an OTP, in that the brute 
force decryption would yield several plaintexts of contradictory 

in practice, though,
the attacking program could just brute force the keyspace of the re-
encrypted ciphertext, 
until it would get a ciphertext that would decrypt to a real 
unless there is a way to re-encrypt the ciphertext in a way that it 
could produce multiple different plaintexts when using different 
session keys, it wouldn't work

for me,
the book presented interesting crypto concepts that would be 
fascinating if explored ...


any ads or links below this message are added by hushmail without 
my endorsement or awareness of the nature of the link

Chart your path to success with a smart new business plan. Click here!

More information about the Gnupg-users mailing list