You can write Your Own Algorithms and method for this..
But Till now there is no any efficient method for providing securiy to exe.
Because HACKERS AND CRACKERS are masterminds..
You can use any third party Software (softwares DLL) at time of Creating Your EXE.w to create Trial period Software exe.
You can clear your concept from these Links and use your own method to provide security to your Application..
Your invention or try may be become most secure in world.. for that world is till waiting.
All the best
This might Help You..