Make the protection certificate valid for one-time only
Hello,
I know how to protect a pdf and save the private key. after saving the private key any person have this key and install it to his/her computer will have access to the pdf. If I am creating my pdf and sharing it with students with the same key for everyone they will be able to share it with others, so how can I make a private key that is valid only for one time (a single computer only) If there is no such a way, what is other suggests that you have for the mentioned incident?
Thanks,