To Protect a File

Enable File Protection functionality.
Protect the file with a certificate or a password.
Create licenses for users to access the protected file.
You can create certificate, password and/or everyone licenses.
(Optional) Identify digital rights-compliant applications.
Distribute protected file to the appropriate users.

PROTECT FILEOPEN allows direct opening of protected files and certificates.
PROTECT FILEOPEN [PASSWORD | CERTIFICATE] <filename><passwordOrCertname> allows you to open a file and make it the active file. The ability to specify a password or certificate is useful for macros or applications that want to work with the protected files but do not want the user to be prompted for credentials.

Note: PROTECT LICENSE ADD CERTIFICATE , PROTECT LICENSE ADD EVERYONE, and PROTECT LICENSE ADD PASSWORD allow you to create licenses.