| When data is written to portable digital media such as thumb drives, floppy diskettes, compact disks, magnetic tape etc, there is risk of data loss. An organizational assessment of risk guides the selection of media and associated information contained on that media requiring restricted access. Organizations need to document in policy and procedures, the media requiring restricted access, individuals authorized to access the media, and the specific measures taken to restrict access. Fewer protection measures are needed for media containing information determined by the organization to be in the public domain, to be publicly releasable, or to have limited or no adverse impact if accessed by other than authorized personnel. In these situations, it is assumed the physical access controls where the media resides provide adequate protection. The employment of cryptography is at the discretion of the information owner/steward. The selection of the cryptographic mechanisms used is based upon maintaining the confidentiality and integrity of the information. The strength of mechanisms is commensurate with the classification and sensitivity of the information. When the organization has determined the risk warrants it, data written to portable digital media must be encrypted.
Rationale for non-applicability:
The MOS SRG requires this control. More specifically, it requires that the operating system cryptographically bind the removable media to the mobile device so data stored on the media card can only be read by that mobile device. In this context, further application controls would be redundant and could cause conflicts resulting in denial of service. |
