Section X.3.5 is optional; if absent, the Media Storage Application Profile is unsecure and the Secure DICOM File Format shall not be used for any DICOM File in the File-set.

If present, this section defines the Media Storage Security Profile to be used for encapsulating allDICOM Files in the File-set, including the DICOM Directory. If this section is present, the Media Storage Application Profile is called Secure Media Storage Application Profile.