reversible whole number license key

From: Thor Russell (thor.russell_at_paradise.net.nz)
Date: 08/05/03 

Date: 4 Aug 2003 16:11:05 -0700

Hi,
I am writing a network license for a software program, and want to use
a serial code to specify the number of licenses a user has. What this
means is that say the user buys 10 licenses, and it given the code
5634853215. They enter this into the computer, and it verifies that it
is a correct code and informs them that they have 10 licenses. In
order to do this I need an easily reversible mathematical operation
that takes one ten digit number e.g. 5634853215 and converts it to
0000000010 (the first 7 zeros are a way of checking that the number is
valid, entering in a random number shouldnt give 7 zeros to start
with). It cant be anything too obvious like just subtracting a number
off the code. I tried using a matrix multiply for each digit, making a
vector out of them, but the inverse matrix is ugly, not consisting of
whole numbers.
Any ideas?
thanks

Thor

Relevant Pages

  • Re: Island Computers is moving
    ... I find it hard to imagine that the associated licenses would ... exceed a low five digit figure. ... (and, BTW, it is beyond my comprehension that commodity ...
    (comp.os.vms)
  • RE: Help! TS CALs are active and installed, but not working!
    ... Our clients are win2k and use RDP to connect. ... Our licenses have been activated and reactivated:P ... Right now we are running off the temporary licenses, ... > We made a regedit to specify the IP of the licensing server here ...
    (microsoft.public.windows.terminal_services)