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Network security

Network security is a computer science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Network security rather than just read about it. In short: Network security is an umbrella term to describe security controls, policies, processes and practices adopted to prevent, detect and monitor unauthorized access, misuse, modification, or denial of a computer network and network-accessible resources. Network security involves the authorization of access to data in a network, which is controlled by the network administrator.

Key takeaways

  • Network security belongs to computer science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Network security to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Network security from memory before moving on to harder problems.

Reference excerpt

Network security is an umbrella term to describe security controls, policies, processes and practices adopted to prevent, detect and monitor unauthorized access, misuse, modification, or denial of a computer network and network-accessible 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 name—i.e., the password—this is sometimes termed one-factor authentication. With two-factor authentication, something the user 'has' is also used (e.g., a security token or 'dongle', an ATM card, or a mobile phone); and with three-factor authentication, something the user 'is' is also used (e.g., 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. Though effective to prevent unauthorized access, this component may fail to check potentially harmful content such as computer worms or Trojans being transmitted over the network. Anti-virus software or an intrusion prevention system (IPS) help detect and inhibit the action of such malware. An anomaly-based intrusion detection system may also monitor the network like wireshark traffic and may be logged for audit purposes and for later high-level analysis. Newer systems combining unsupervised machine learning with full network traffic analysis can detect active network attackers from malicious insiders or targeted external attackers that have compromised a user machine or account. Communication between two hosts using a network may be encrypted to maintain security and privacy. Honeypots, essentially decoy network-accessible resources, may be deployed in a network as surveillance and early-warning tools, as the honeypots are not normally accessed for legitimate purposes. Honeypots are placed at a point in the network where they appear vulnerable and undefended, but they are actually isolated and monitored. 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 attacker's 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 attacker's methods can be studied and that information can be used to increase network security. A honeynet typically contains one or more honeypots. Previous research on network security was mostly about using tools to secure transactions and information flow, and how well users knew about and used these tools. However, more recently, the discussion has expanded to consider information security in the broader context of the digital economy and society. This is indicative of network security topics covering not just individual users and tools, but also conversations about the larger culture of information security in our digital world.

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 high-maintenance and advanced software and hardware to prevent malicious attacks from hacking and spamming. In order to minimize susceptibility to malicious attacks from external threats to the network, corporations often employ tools which carry out network security verifications. These tools can also mitigate and detect internal human behavior such as insider threats and email storms. The human element is often the weakest link in any network security system, as evidenced by a study in 2014 which found that employees often do not see themselves as part of their organization's information security effort and often take actions that impede organizational changes. The move from centralized systems to cloud-based and hybrid work environments has made it harder to monitor networks, especially with traditional tools. A Broadcom survey found that 65% of respondents rely on third-party network providers, which creates blind spots and makes systems more vulnerable. Dependence on third parties also reduces an organization's direct control over its network infrastructure, making it harder to implement advanced monitoring processes.

Types of attack Networks are subject to attacks from malicious sources. Attacks can be from one of two categories: passive and active. A passive attack occurs when a malicious actor intercepts data traveling across a network, usually without generating any kind of alerts. It can be difficult or impossible to know if this kind of attack has occurred. For example, a wardriving attack can wirelessly detect the four-way handshake between an access point and a client, and crack the password offline without the owner of the access point ever knowing. An active attack occurs when a malicious actor initiates commands targeting the network or network resources. This is generally meant to disrupt the network's normal operation, conduct reconnaissance, or attempt lateral movements to find and gain access to assets available via the network. Types of attacks include:

… excerpt ends here. Continue reading the full article.

Worked examples

Example 1 — a first encounter with Network security

Start with the simplest possible case. Write down what Network security claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In computer science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Network security before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Network security ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Network security

In research
Network security appears in computer science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Network security in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Network security is common in secondary-school and first-year university syllabi. It links to neighbouring topics Computer network security, Cybersecurity engineering, so understanding it makes those chapters shorter.
In everyday life
Look for Network security outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Network security in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Network security means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Network security out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Network security in simple terms?

Network security is an umbrella term to describe security controls, policies, processes and practices adopted to prevent, detect and monitor unauthorized access, misuse, modification, or denial of a computer network and network-accessible resources. Network security involves the authorization of ac…

Why does Network security matter?

Because it connects several computer science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Network security?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Network security.

Tags

  • Computer network security
  • Cybersecurity engineering

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