Using any of the key terms listed at the end of chapter 9 "Attached",explain what it is and how it relates tonetwork security. Consider how it may be used to either make your network more secure or explain how it is used by hackers/bad actors to compromise or exploit hosts on the network.Youhave the freedom to exploreany aspect of your selected security term.

Key Terms backdoor A program installed on a computer that permits access to the computer, thus bypassing the normal authentication process. client-to-site VPN mode This VPN mode establishes a VPN connection between a single client computer and a VPN device. content filter A type of firewall or security device that looks for key words or phrases in the data portion of each packet to determine whether to allow it into the network. demilitarized zone (DMZ) The part of a network that contains publicly accessible devices, such as Web servers and VPN servers, but is still protected by a firewall. denial-of-service (DoS) attack An attempt to tie up network bandwidth or services so th network resources are rendered useless to legitimate users. digital certificates Digital documents used in encryption and authentication protocols that identify a person or computer and can be verified by a certification authority. encryption A technology used to make data unusable and unreadable to anyone except authorized users of the data. Extensible Authentication Protocol (EAP) A framework for other authentication protocols that provides encryption and authentication.