A fiber optic cable is a physical medium that is capable of conducting modulated light trasmission. Fiber optic cable carries signals as light waves, thus creating higher trasmission speeds and greater distances due to less attenuation. This type of cabling is more difficult to tap than other cabling and is most resistant to interference, especially EMI. Source: KRUTZ, Ronald L. & VINES, Russel D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, John Wiley & Sons, 2001, Chapter 3: Telecommunications and Network Security (page 103).