I am looking for ideas on how to develop a key generator. I have been asked by someone to develop a key generator him. I know how to do CRC checks, but I don''t really know the idea behind a key algorithm. I am looking for a modulair way of doing things. This means, my application has 5 modules(For example). My customers buys 3 components and the other 2 are left out. How would I do this? And for instance, is there a way to incorporate a name into it aswell? I am not looking for an MD5 or something, but a nice idea for key generating... Toolmaker My site /* -Earth is 98% full. Please delete anybody you can.*/

I'd say you have to use non symetric chipper:

You generate a private and a public key for all your application.
Now per customer you have the identifier string of the customer, and the key to unlock your program.

Say, the customer is "Toolmaker" (like a serial number)
now you calculate the hashsum of this and chipper it with your private key.
The result is the validation-key.

now on the customer side the program pops up, requesting to enter the serial number (enter "Toolmaker") and the validation key.
Both entered, you will calculate the hashsum of the serial number, and compate it with the dechippered (used the public key here). If they match, the entered key is valid and you can activate the functionality of your program.

hmmm... i think this is a bad description on how to do it, do a google search for "digital signature" to learn more about it. that should give you a good idea on how this is done.

Edit:
this is a good link about digital signature
you also can try to check for PGP (Pretty good privacy), a program that can digital sign stuff



[edited by - OmniBrain on April 23, 2004 6:51:26 AM]

x ^ y mod z = a

the serial has the x, y and z, (taken from the internet, from your server), the a is the end part of the user

Firts 6 numbers - X, second 6 numbers Y, last 5 Z.

I build something ike this a while back...