Question

Consider I have created software and want to make that soft to be activated via internet if it is being purchased (more precisely, if a license has been purchased). What is the contemporary way of making software safe from using without purchasing a license (from hacking)? How the software and license database should interact to make a robust system of safety against hacking but still not breaking the convenience and ease of use of the soft (In details please)?

NOTE: I know that completely to do that is impossible. There is no way against hacking. I am asking about decreasing possibility of hacking.

Answer 1

This is a very good article from the creator of the successful MacOS X text editor TextMate.

The basic concepts:

• create a public/private key-pair once

On the server

• create a hash of some user details
  (name or e-mail adress, …)
• encrypt the checksum with the private key
• send the user a mail including the generated license key

On the client

• use OpenSSL and your public key to validate the licence