Encrypts Pdf file with userpassword and ownerpassword and sets the documents privileges to access. The user password and the owner password can be null or empty. The owner password will be replaced with a random string if the input owner password is null or empty. Does not throw an exception if process failed....TryEncryptFile method Encrypts Pdf file with userpassword...40 bits encryption, KeySize.x128 for 128 bits encryption and KeySize...