Need advice and recommendations

Hi guys,

I'm putting the finishing touches to a software I plan to sell shortly.
I would like it to be secure to prevent too much sharing.

Any of you know of a way (possibly with a third party Cie) to make it so when the customer buys, he/she gets a username and password and the software would verify the identity of the user before being able to use it?

Any input will be appreciated.

Again, thanks