Re: LZ: Self Encrypting Programs

To: list-zshell@lists.ticalc.org
Subject: Re: LZ: Self Encrypting Programs
From: "Michael Wyman" <Michael.J.Wyman-1@tc.umn.edu>
Date: Tue, 3 Dec 1996 14:58:32
Reply-To: list-zshell@lists.ticalc.org

On Tue, 3 Dec 1996 10:42:52 -0500 (EST),
Daniel Knapp wrote...
>> If you have it rewrite itself at the begining it should loose the revert
>> to original when it exits lots of computer programs did this to prevent
>> people from modifying them.
>
>  But you forgot - the 85 has no hard disk.  The "stored copy" is
>literally running in place; there is no second copy, so it can't be
>discarded.
>  And couldn't someone just make a program to decrypt it and leave it that
>way?
>
>                     /***********************************
>                     *           Daniel Knapp           *
>                     *       FeatherWate Software       *
>                     *     email: dankna@bergen.org     *

It's true that somebody could write a program which could decrypt the code 
and leave it that way, but that would take some time.  The encryption would 
help keep people (except those who really want to) from looking at the 
code.  There might be a few reasons for doing this, like keeping people 
from decrypting the passwords in password protect programs (like KCLock85 
and SecureIt-85, PWProt, PassWord, etc.).  For most programs, the code is 
released anyways, or at least some routines from the code.

Don't take this as flaming, it isn't meant to be.  You made a good point!

Thanks,
Michael Wyman
wyma0012@gold.tc.umn.edu