B. Option B defines the time-of-check TOC, which is the time at which a subject verifies the

damage to tape media, shortening its life span. Here are some useful guidelines for handling media: Keep new media in its original sealed packaging until it’s needed to keep it isolated from the environment’s dust and dirt. When opening a media package, take extra caution not to damage the media in any way. This includes avoiding sharp objects and not twisting or flexing the media. Avoid exposing the media to temperature extremes; it shouldn’t be stored too close to heat- ers, radiators, air conditioners, or anything else that could cause extreme temperatures. Do not use media that has been damaged in any way, exposed to abnormal levels of dust and dirt, or dropped. Media should be transported from one site to another in a temperature-controlled vehicle. Media should be protected from exposure to the outside environment; avoid sunlight, moisture, humidity, heat, and cold. Always transport media in an airtight, waterproof, secured container. Media should be acclimated for 24 hours before use. Appropriate security should be maintained over media from the point of departure from the backup device to the secured offsite storage facility. Media is vulnerable to damage and theft at any point during transportation. Appropriate security should be maintained over media at all other times including when it’s reused throughout the lifetime of the media until destruction. Storing Media Media should be stored only in a secured location in which the temperature and humidity is con- trolled, and it should not be exposed to magnetic fields, especially tape media. Elevator motors, printers, and CRT monitors all have strong electric fields. The cleanliness of the storage area will directly affect the life span and usefulness of media. Access to the storage facility should be controlled at all times. Physical security is essential to maintaining the confidentiality, integrity, and availability of backup media. Managing Media Life Span All media has a useful life span. Reusable media will have a mean time to failure MTTF that is usually represented in the number of times it can be reused. Most tape backup media can be reused 3 to 10 times. When media is reused, it must be properly cleared. Clearing is a method of sufficiently deleting data on media that will be reused in the same secured environment. Purg- ing is erasing the data so the media can be reused in a less-secure environment. Unless absolutely necessary, do not employ media purging. The cost of supplying each classification level with its own media is insignificant compared to the damage that can be caused by disclosure. If media is not to be archived or reused within the same environment, it should be securely destroyed. Once a backup media has reached its MTTF, it should be destroyed. Secure destruction of media that contained confidential and sensitive data is just as important as the storage of such