From: dlv@bwalk.dm.com (Dr.Dimitri Vulis KOTM)
Date: Wed, 12 Nov 1997 08:57:44 +0800
To: cypherpunks@toad.com
Subject: Re: Content controls
In-Reply-To: <v0310280db08e8afb9644@[207.167.93.63]>
Message-ID: <8k61Fe4w165w@bwalk.dm.com>
MIME-Version: 1.0
Content-Type: text/plain



Tim May <tcmay@got.net> writes:
> Even purely digital works are easily copied. Even unique IDs per software
> piece are easily removed (e.g., by having N customers compare and diff out
> the noncommon bits).

About 15 years ago I was trying to break the code in some software
distributed by some Canadian folks... (It was cheap to buy, and
I was doing it for fun.) Basically, every customer's executables
were almost completely different because they were encrypted with
a totally different key and decrypted at runtime.  The trick was to
disassemble the decryption code and to compare the decryption
results from two copies to see where the customer name was embedded.

---

Dr.Dimitri Vulis KOTM
Brighton Beach Boardwalk BBS, Forest Hills, N.Y.: +1-718-261-2013, 14.4Kbps