445 Copyright Goodheart-Willcox Co., Inc. AAA proxy application gateway asymmetric-key encryption authentication authentication, authorization, and accounting (AAA) backdoor biometrics certifi cate authority (CA) Challenge Handshake Authentication Protocol (CHAP) circuit-level gateway content fi lter demilitarized zone (DMZ) Denial of Service (DoS) Diameter digital certifi cate encryption Extensible Authentication Protocol (EAP) fi rewall signature identifi cation hashing Health Insurance Portability and Accountability Act (HIPAA) honey pot Internet Protocol Security (IPSec) intrusion detection system (IDS) intrusion prevention system (IPS) Kerberos Lightweight Extensible Authentication Protocol (LEAP) logic bomb macro virus malware man in the middle (MITM) media access control (MAC) fi lter Microsoft Challenge Handshake Authentication Protocol (MS-CHAP) packet fi lter packet sniff er Password Authentication Protocol (PAP) Payment Card Industry Data Security Standard (PCI DSS) phishing port monitoring Protected Extensible Authentication Protocol (PEAP) protocol analyzer proxy server ransomware Remote Authentication Dial-In User Service (RADIUS) replay attack rogue access point Secure Copy Protocol (SCP) Secure Shell (SSH) Secure Sockets Layer (SSL) smart card Smurf attack social engineering spoofi ng stateful packet inspection stateless packet inspection symmetric-key encryption Terminal Access Controller Access-Control System Plus (TACACS+) Transport Layer Security (TLS) transport mode Trojan horse tunnel mode virtual network connection (VNC) virus worm Zero Confi guration (Zeroconf) Overview Th is chapter presents the basics of network security. All network users need user and system policies that are set in place and enforced. Policies outline how users are to use and not use their workstations and the network. Basically, policies and proce- dure are a list of dos and don’ts for the users. Typically, this procedural list is referred to as an acceptable use policy. In this chapter, you will receive a general overview of security systems and prin- ciples. Security often begins with authentication. Th is is simply the process of en- suring the user is indeed who he or she claims to be. Th ere are many methods for authenticating a user, some specifi cally designed to make it extremely diffi cult to circumvent the authentication process. Regardless of which one is utilized, all au- thentication methods have the same fi nal goal: to verify a user’s identity. Some examples of authentication methods include digital certifi cates, smart cards, and biometrics. We will look at these and other methods of authentication as well as security protocols and security methods, such as encryption, authorization, and accounting. Th e fi eld of network security is vast and complex. Th is chapter covers only the basics. A complete presentation of network security would require an entire course with a textbook completely dedicated to network security and an intensive series of lab activities. Key Terms