3.2 Understand the security concerns for the following types of media
o Coaxial Cable
o UTP / STP (Unshielded Twisted Pair / Shielded Twisted Pair)
o Fiber Optic Cable
o Removable Media
o Tape
o CD-R (Recordable Compact Disks)
o Hard Drives
o Diskettes
o Flashcards
o Smartcards
Coaxial Cable
Coaxial cable is a bus technology sometimes used for networking (usually UTP/STP is used now). The two types are 10Base5, or thicknet, (thick cable w/ metallic core surrounded by dielectric, mesh, and sheath - 500 meters max length) and 10Base2, or thinnet, (thinner, but 185 meters max).
Coaxial cables must be terminated. Vampire taps are used to connect clients (nodes) to the central cable, but attackers can do the same. The probllem was that if one device went bad, or one connection "leaked," the whole network would crash and it would take a long time to find the faulty device.
UTP/STP
UTP stands for unshielded twisted pair and STP stands for shielded twisted pair. These are most popular, and smaller than coax. Inside is a solid copper wire and a sheath. The wires are twisted to prevent cross talk and lessen the "noise." UTP just has a sheath, and STPs a "shield." The cables are vulnerable to electromagnetic interference EMI, so they should not be near power cables. Also, there are devices that can pick up on "leakage" on eavesdrop on conversations. It can also be tapped at the device (router, switch, etc).
Fiber Optic
Fiber Optic cable is the most secure and fastest, but the most expensive and hardest to install. It is possible to tap, but it is very difficult and likely to be noticed. Fiber Optic usually uses glass (sometimes plastic) as a core. It doesn't send electrical signals, so there can be no EMI. There is a "cladding" around the core that keeps light inside the core. There is a jacket surrounding the cable.
Removable Media:
Removable media can help to transfer files and/or backup data, but their small size makes them fairly easy to steal. Any removable media should be "sanitized" meaning that all data should be erased and rendered impossible to read when disposed.
Tape
Tape is a common form of storage for backup that offers more storage than CDs. Eventually, tapes are worn out since they are mechanical in nature, so they should be reused a limited number of times.
CD-R
CD-Rs helped replace floppies, although they still do not have any form of access control or encryption. They are more difficult to erase by accident.
Hard Disk Drive
Hard drives offer very large storage capacities and access control. They allow encryption more easily than other media.
Diskettes (floppies)
These are low-storage (1.44 MB standard) devices. They aren't as common any longer due to flash memory, which is more dense and not mechanical. Many new computers do not come with floppy drives any more. There is no method of access control or any form of security. They cannot come near a magnetic field since data is stored magnetically.
Flashcards
Very small cards that use flash technology for memory storage. These are popular for use in mobile devices such as PDAs, digital cameras and MP3 players.
Smartcards
These are also very small. These often contain memory and a method of processing-- a microprocessor, read-only memory (ROM) random access memory (RAM) electrically erasable programmable ROM (EEPROM). They are often used for authentication and access control.