Data storage devices are magnetic and optical devices or media designed to retain data. Storage devices include: hard drives, floppy disks, magnetic tapes, compact discs (CDs), digital video disks (DVDs), flash memory cards and flash drives. Three issues to take into account with the security of data storage devices:
- Even after the information has been erased, data residue may remain on storage devices making the data retrievable. The same applies with a disk that has been reformatted.
- Data storage devices are vulnerable to theft.
- Data storage devices are also susceptible to unauthorized access, particularly removable storage devices, such as floppy disks, flash memory cards and flash drives.
Input and output devices can introduce security risks to a system. A technology known as TEMPEST, for example, can weaken security of data displayed on a monitor. With TEMPEST an electronic discharge from the monitor can be read from a remote location. Printouts are also security risks should an unauthorized person access sensitive documents.