network security this article is part of a series oninformation security related security categories internet security cyberwarfare computer security mobile security network security threats computer crime vulnerability eavesdropping malware spyware ransomware trojans viruses worms rootkits bootkits keyloggers screen scrapers exploits backdoors logic bombs payloads denial of service defenses computer access control application security antivirus software secure coding secure by default secure by design secure operating systems authentication multifactor authentication authorization datacentric security encryption firewall intrusion detection system mobile secure gateway runtime application selfprotection rasp vte network security consists of the policies and practices adopted to prevent and monitor unauthorized access misuse modification or denial of a computer network and networkaccessible resources network security involves the authorization of access to data in a network which is controlled by the network administrator users choose or are assigned an id and password or other authenticating information that allows them access to information and programs within their authority network security covers a variety of computer networks both public and private that are used in everyday jobs conducting transactions and communications among businesses government agencies and individuals networks can be private such as within a company and others which might be open to public access network security is involved in organizations enterprises and other types of institutions it does as its title explains it secures the network as well as protecting and overseeing operations being done the most common and simple way of protecting a network resource is by assigning it a unique name and a corresponding password network security concept network security starts with authentication commonly with a username and a password since this requires just one detail authenticating the user nameie the passwordthis is sometimes termed onefactor authentication with twofactor authentication something the user has is also used eg a security token or dongle an atm card or a mobile phone and with threefactor authentication something the user is is also used eg a fingerprint or retinal scan once authenticated a firewall enforces access policies such as what services are allowed to be accessed by the network users communication between two hosts using a network may be encrypted to maintain privacy honeypots essentially decoy networkaccessible resources may be deployed in a network as surveillance and earlywarning tools as the honeypots are not normally accessed for legitimate purposes techniques used by the attackers that attempt to compromise these decoy resources are studied during and after an attack to keep an eye on new exploitation techniques such analysis may be used to further tighten security of the actual network being protected by the honeypot a honeypot can also direct an attackers attention away from legitimate servers a honeypot encourages attackers to spend their time and energy on the decoy server while distracting their attention from the data on the real server similar to a honeypot a honeynet is a network set up with intentional vulnerabilities its purpose is also to invite attacks so that the attackers methods can be studied and that information can be used to increase network security a honeynet typically contains one or more honeypots security management security management for networks is different for all kinds of situations a home or small office may only require basic security while large businesses may require highmaintenance and advanced software and hardware to prevent malicious attacks from hacking and spamming types of attacks networks are subject to attacks from malicious sources attacks can be from two categories passive when a network intruder intercepts data traveling through the network and active in which an intruder initiates commands to disrupt the networks normal operation or to conduct reconnaissance and lateral movement to find and gain access to assets available via the network types of attacks include passive network wiretapping port scanner idle scan encryption traffic analysis active virus eavesdropping data modification denialofservice attack dns spoofing man in the middle arp poisoning vlan hopping smurf attack buffer overflow heap overflow format string attack sql injection phishing crosssite scripting csrf cyberattack cloud computing security crimeware cyber security standards data loss prevention software greynet identitybased security metasploit project mobile security netsentron network security toolkit tcp gender changer tcp sequence prediction attack tcp sequence prediction attack timeline of computer security hacker history wireless security dynamic secrets low orbit ion cannon high orbit ion cannon case study network clarity sc magazine 2014 cisco 2011 what is network security retrieved from ciscocom security of the internet the froehlichkent encyclopedia of telecommunications vol 15 marcel dekker new york 1997 pp231255 introduction to network security matt curtin mpls sdwan and network security yishay yovel security monitoring with cisco security mars gary halleengreg kellogg cisco press jul 6 2007 selfdefending networks the next generation of network security duane decapite cisco press sep 8 2006 security threat mitigation and response understanding csmars dale teschgreg abelar cisco press sep 26 2006 securing your business with cisco asa and pix firewalls greg abelar cisco press may 27 2005 deploying zonebased firewalls ivan pepelnjak cisco press oct 5 2006 network security private communication in a public world charlie kaufman radia perlman mike speciner prenticehall 2002 isbn network infrastructure security angus wong and alan yeung springer 2009 