Security Issues Related to Network Media and Removable Media

Media security has two primary components: cabling media security and removable media security.

Cabling Security

Cabling is often an overlooked aspect of designing a security for a network. Unfortunately, cabling problems are a common cause of network failures. Cabling should be protected from unauthorized physical access. We must also be considerate of what type of cable is the most appropriate for our environment. For example, we should know if interference may be present in our environment.

There are three types of of cabling we should know about. First is coaxial cable. It comes in two types: thinnet and thicknet version. Thinnet coax is RJ-58, and can also be called 10base2. It uses BNC connectors and has a 185 m maximum length. Thicknet or RGA cable also known as 10base5, uses vampire tabs for connections and has a maximum length of 500 m. Coax cabling requires termination and grounding for proper use. It is vulnerable to interference, has distance limitations, and communication over coax cable can be intercepted.

UTP and STP are another type of cabling (Unshielded Twisted Pair and Shielded Twisted Pair). These two types of wiring are exactly the same, except that STP has additional layer of aluminum foil as which serves as shielding. Maximum length is hundred meters, and can also be called 100baseT. It uses RJ-45 connectors. UTP and STP cables are vulnerable to interference, although STP is  slightly less vulnerable than UTP. It also has distance limitations and can also be subject for eavesdropping.

Third type of cabling is a fiber optic cabling. Fiber optic cabling is made up of glass or plastic. It has ability to transmit communications by using pulses of light rather than electricity. It can span long distances, and is resistant to most forms of interference. It is also difficult to intercept.

Removable Media Security

Removable media is any type of storage device that can store data and be easily removed or transported to other locations. Removable media poses a serious security risk because it can host confidential, sensitive and valuable information. The presence of a removable media drive on a computer system reduces its physical security. Some examples of removable media include tape drives, CD and DVD writers, removable hard drives, flash cards, memory sticks and even smart cards. When using removable media in a secure environment, we need to consider how to destroy that media at the end of its useful lifetime. Removable media along with printouts should be properly destroyed instead of being thrown away. Destruction can be done using incineration, crushing and acid dipping. 

Smart cards can contain authorization credentials such as digital certificates or cryptographic keys. It is important not to share smart cards among multiple individuals users. We should always maintain physical control of possession of smart cards in order to keep security intact.