Re: Cracking decrypted file when knowing partial contents

From: smith8328 t'kri _at_bellsouth.net (smith8328_at_bellsouth.net)
Date: 04/21/04 

Date: 21 Apr 2004 01:24:02 -0700

Joe Peschel <jpeschel@no.spam.org> wrote in message news:<Xns94D199CA9B3ADfa0khgj7ji8i8jo9@216.168.3.44>...
> "Adfa" <adfa@noname.com> wrote in news:c634fb$7qi$1@bunyip.cc.uq.edu.au:
>
> > Would it be easier to crack an encrypted file if the cracker knew some
> > of the contents of the file?
>
> Yes, but it depends upon the encryption method.
>
> >
> > For example, an encrypted MS Word file where the cracker knew
> > word-for-word a few paragraphs of the document, but not necessarily
> > the exact byte postions of those paragraphs in the file.
> >
>
> You can drag the known-plaintext through various positions in the file.
>
> J
The downfall of most encryption systems is that people are so quick to
fall into
habit. They start their messages with the same headings, use the same
words, phrases, and sentences over and over again. This is especially
true in Military
Communications. That is why a one-time pad/cryptsystem is an absolute
must.

     Having a little information about your target and his habits will
allow
entry into virtually any system he creates.

     Besides,...when all else fails...use brute force.

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