safedisk is not possible. its only possible for
mechanical duplication and is very much $$$ in license
the only chance you have is to protect your exe, there
are some exe protecting programs outthere which
can lock your exe after a peroid of time or executions.
The only way to use this exe anymore is to recieve
an unlock key from you via email.
i know a program called visual protect, this should do the job.