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Path: utzoo!linus!decvax!harpo!seismo!hao!hplabs!hp-pcd!john
From: john@hp-pcd.UUCP (John Eaton)
Newsgroups: net.crypt
Subject: Re: software piracy and coupons - (nf)
Message-ID: <2361@hp-pcd.UUCP>
Date: Tue, 8-Nov-83 03:23:33 EST
Article-I.D.: hp-pcd.2361
Posted: Tue Nov  8 03:23:33 1983
Date-Received: Wed, 9-Nov-83 07:15:13 EST
Sender: netnews@hp-pcd.UUCP
Organization: Hewlett-Packard, Corvallis OR
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#R:allegra:-194700:hp-pcd:42000002:000:1590
hp-pcd!john    Nov  7 12:54:00 1983

Any program can be pirated if the pirate has the resources and determination
to do it. The trick is to make the pirate spend more time breaking the scheme
than it would take him to rewrite the program.

Protection schemes that can be NOPed over are at best a minimal attempt at
security. The prudent programmer will back up his protection schemes with
code that verifies that the program is intact and unmodified. Several
independent schemes are usually better than one. 

Progams that detect a copy violation and immediately go out and trash the
disc or memory are inviting someone to backtrace and figure out how the
violation was detected. A program is better off waiting 20 or 30 seconds after
detecting an error to do something about it. That gives the pirate a few 
million more lines of code to sift through. Ideally the error condition should
be "laundered" by passing it through several intermediate stages to make it
difficult to figure out where it originated from.

A really sneaky programmer will not wipe out the program if it is copied but 
will modify it enough to make it unusable. During program development you 
should save the worst bug that you find (you know the one that took 3 days
of debugging to find) and reinstall it if the program has been copied. Perhaps
you can even leave the bug in and have your copy detection routines remove it
if its a legal copy.

The pirate will always have the ability to break a program. The only thing that
a programmer can do make the "Work Function" great enough to discourage the
lightweights.



John Eaton

hplabs!hp-pcd!john