Copy protection

Richard Gaskin ambassador at fourthworld.com
Fri Apr 4 05:02:01 EST 2003


mazzapaolo at liber wrote:

> Thank you for your  insights. I know it is impossible to prevent application
> to be copyed.
> I was looking for a "trivial  protection", an "unlock code" linked to the name
> of the user similar to the unlock code of revolution.
> So, I had my application to register the name of the user in a file, stored
> in the preferences folder.
> I wondered how lonk my code to the the name of the user.
> ChartoNum function wuold be a solution, but is is too trivial, I think.

You can use that as a part of a larger but not necessarily complex
algorithm.

Remember that all you need is two routines:  one for your use to generate
reg keys, and one in the program to verify validity of a key.

In the simplest sense, a key is the result of applying a set of rules to
create a hard-to-guess string of between 8 and 20 characters.

Just pick a length that you like (I personally get annoyed at entering long
reg codes, so I keep them to under 14 characters and allow them to be
pasted), and think of some rules to create such a string,like the sum of the
first two chars divided by 2 is the last character, etc.  There are a nearly
infinite variety of schemes you could come up with, potentially quite deep.
esp. when you consider the breadth of string and number functions in
Transcript.

It's kinda fun to play with, but easy to get too wrapped up in it as Kee
noted.  I've found it more important to focus on being able to change my reg
scheme frequently. 

I put in a completely different algorithm every few feature releases, so if
someone has become addicted to a pirated earlier version and I've done my
job in providing attractive feature additions, as long as my product's price
is reasonable sooner or later it's simpler for them to just become a
customer.

-- 
 Richard Gaskin 
 Fourth World Media Corporation
 Developer of WebMerge 2.2: Publish any database on any site
 ___________________________________________________________
 Ambassador at FourthWorld.com       http://www.FourthWorld.com
 Tel: 323-225-3717                       AIM: FourthWorldInc




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