Enigma Protector

how its made every 3 months I sent ativation key to the user, without having to send the application again.

Hi obeng

That is too simple, While you are generating registration key for your protected application, In "Key properties" section, check "Days" and set its value into 90.
Then after 90 days the user should re-register the app, then again you will generate a 90 days registration key and a loop will be created

See this image: Or you can see this tutorial here: http://www.enigmaprotector.com/forum/vi ... =27&t=1473

Thanks Majid,
one more question, whether this way is quite safe??
sorry i don't understand much about this.

Hi obeng, yes, you can use the way Majid advised. Thanks Majid!

But I would like to recommend you to use Expiration Date instead (in the keys generator). And to avoid clock reversing by user, use the option Trial Control - Time Control.