1998-08-06 - RE: compression vs encryption

Header Data

From: “Brown, R Ken” <brownrk1@texaco.com>
To: Anonymous <bbt@mudspring.uplb.edu.ph>
Message Hash: d4b0f7cc4b4428654b96b73eaa25c8dcacf57cad9ffb63ee15a546de9aba7a06
Message ID: <896C7C3540C3D111AB9F00805FA78CE2013F8317@MSX11002>
Reply To: N/A
UTC Datetime: 1998-08-06 10:44:52 UTC
Raw Date: Thu, 6 Aug 1998 03:44:52 -0700 (PDT)

Raw message

From: "Brown, R Ken" <brownrk1@texaco.com>
Date: Thu, 6 Aug 1998 03:44:52 -0700 (PDT)
To: Anonymous <bbt@mudspring.uplb.edu.ph>
Subject: RE: compression vs encryption
Message-ID: <896C7C3540C3D111AB9F00805FA78CE2013F8317@MSX11002>
MIME-Version: 1.0
Content-Type: text/plain

> Bernardo B. Terrado[SMTP:bbt@mudspring.uplb.edu.ph]  seemed to write:
> What's the difference between compression and encryption?

Eh?   Encryption means keeping things secret. Compression is keeping
them small.  Not the same thing at all.  OK, they might use some of the
same tools - but you can use a screwdriver to clean your nails.

> Correct me if I'm wrong,  in compression we lose something, like in 
> image compression and audio compression,  but in encryption, we don't.

Be corrected. You are wrong. There are ways of compressing that don't
lose anything (like PKzip that you might have heard of...). There  are
ways of encrypting that don't compress. (in fact you might not want
totally efficient compression in encryption because that might give an
eavesdropper clues as to the real length of the plaintext which could be
useful to them)

> > One sure protection againts evil hackers is encryption (?),
> but what if that evil hacker deletes the ciphertext file and the
> plain  text file (that is assuming the evil hacker just deletes 
> every file he wants to delete).

I go to the backup, that's what. If I care enough about a file to
encrypt it I care enough about it to back it up. Your hacker is doing
what they call a "denial of service" attack. Encrypting your files
doesn't make any difference is someone deletes them. You need different
defences against different kinds of attack.

Or was all this some sort of troll...

> ======================================================================
> =========
> You give the words  you have spoken,
>    it is not lended and are not taken back.
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> bbt@mudspring.uplb.edu.ph
> bbt@peak-two.uplb.edu.ph
> metaphone@altavista.net