Network security encompasses a vast and complex array of technologies and procedures implemented for the purposes of protecting devices and data attached to a home, corporate, or public network.
Due to the breadth of the topic, different organizations are liable to define network security differently. For some, it may represent the safeguarding of the entire network infrastructure through a comprehensive platform from the server to the edge, while others may view it as a more specialized segment within the cybersecurity field, emphasizing the protection of the network connecting devices rather than the devices themselves.
Regardless of its particular focus, network security has three universal, key objectives:
- Preventing unauthorized access to network resources.
- Detecting and stopping cyberattacks and security breaches.
- Ensuring network resources are provisioned to authorized users — and only to them — when and only when they need them.
How does network security work?
Network security works on a principle of establishing multiple defensive layers so that more than one subsystem needs to be violated to compromise the security of the network and access the data. This strategy, known as “defense in depth,” helps in reducing the risk of a single point of failure.
Defense in depth involves a comprehensive system of devices, policies, and practices employed to prevent and monitor unauthorized access, misuse, alteration, or denial of a computer network and network-accessible resources. It starts with user authentication — often using passwords and sometimes two-factor authentication (2FA) — followed by encryption and tokenization of data to ensure the data remains secure even if access is breached.
Network firewalls and virtual private networks (VPNs) are put in place to protect the entire network, while antivirus software or intrusion detection systems (IDS) provide security at the individual or device level.
Additional measures, such as security information and event management (SIEM) systems, and physical security safeguards such as biometrics, fences, CCTV, and guards may be employed to provide a holistic overview of the network’s security.
7 types of network security
Network security is an extensive field comprising multiple types, each with a specific focus. Some of the primary types include access controls, firewalls, IDSs, VPNs, and antivirus software.
1. Network access control (NAC)
Network access control is all about managing who can access your network and what they can do once they’re in. The first level of this is often user authentication, requiring usernames and passwords or even more complex 2FA or multifactor authentication (MFA).
For instance, in a corporate setting, employees might need to enter a username, password, and a code sent to their mobile devices to log in to the network.
Further, NAC often involves policies that restrict users’ permissions within the network such as implementing zero-trust solutions or least privilege policies, preventing users from accessing particular data or applications unless and until they need them.
Think of firewalls as your network’s first line of defense. A firewall could be a hardware device or a software application, which serves as a gatekeeper between your trusted internal network and untrusted external networks, such as the internet.
They use a defined set of rules to allow or block traffic into and out of a network. For example, a firewall might block incoming traffic from a suspicious IP address or only allow traffic on certain types of connections.
3. IDS and intrusion prevention systems (IPS)
IDS and IPS systems scan network traffic to identify and respond to potential threats based on a set of predefined rules or policies.
IDS is a “watchdog,” alerting administrators to potential threats so that they can take action. IPS, on the other hand, is more proactive, automatically taking action to block potential threats without waiting for human intervention.
For example, an IDS might alert administrators to unusually high traffic volumes from a single IP address, while an IPS might block traffic from that IP address automatically.
A VPN creates a secure tunnel for information to travel across the internet, connecting a user’s device to a network. The data inside the tunnel is encrypted, keeping it safe from prying eyes. It also hides the user’s IP address, making it difficult for attackers to track or target the user.
A remote worker, for example, might use a VPN to securely access their company’s internal network from their home.
5. Antivirus and anti-malware
This software is designed to protect against malicious software programs, collectively known as malware. Malware includes threats like viruses, ransomware, and spyware, all of which can harm your network and the devices connected to it.
Antivirus and antimalware software continuously scan for and remove these threats. For instance, an antivirus program might scan a downloaded file before it executes to ensure it doesn’t contain any known threats.
6. Network segmentation
Network segmentation involves splitting a network into multiple smaller networks, each acting as its own separate entity. This reduces the scope of a potential attack and makes it harder for an attacker to move laterally across the network. For instance, a business might keep its payment systems on a completely separate network from its employee email system.
7. Workload security
Workload security is about securing the applications or workloads that operate on your network. This could involve using secure coding practices to prevent application-level attacks or encrypting data at rest and in transit to prevent data leaks. An example might be a cloud-based application that uses SSL encryption to protect sensitive data.
What are common threats to network security?
Network security is continuously under siege from a wide range of threats. Some of the most prevalent ones include malware, phishing, denial of service (DoS), and man-in-the-middle (MitM) attacks. Understanding these hazards is the first step towards mitigating them.
Malware, or malicious software, is an umbrella term that includes a variety of harmful programs like viruses, worms, Trojan horses, ransomware, spyware, adware, and botnets. These programs are designed to infiltrate and damage computers without the users’ consent.
A recent example of damaging malware is the ”WannaCry” ransomware attack in 2017, which affected 10,000 computers every hour and spread to 150 countries like a tsunami, encrypting data and demanding Bitcoin payments in return for data release.
Phishing attacks are deceptive strategies in which the attacker poses as a trustworthy entity to steal sensitive data such as usernames, passwords, credit card information, and social security numbers. They often appear as an email from a well-known organization, such as a bank or credit card company, urging you to update your information on a fake but convincing website.
An infamous instance of a phishing attack occurred in 2022 when Allegheny Health Network suffered the exposure of protected health information (PHI) of approximately 8,000 of their patients.
Denial-of-service (DoS) and Distributed denial-of-service (DDoS) attacks
In DDoS attacks, a network’s servers are overloaded with traffic, leading to a depletion of resources and bandwidth. This makes the network slow or completely unavailable to legitimate users. The most recent significant DDoS attack took place in February 2022 when Ukraine was hit with the largest DDoS attack ever in the country’s history, impacting government websites and financial services.
Man-in-the-middle (MitM) attacks
MitM attacks happen when attackers secretly intercept and potentially alter the communication between two parties who believe they are directly communicating with each other. This could involve eavesdropping on an insecure Wi-Fi network to steal login credentials or altering a transaction to send money to the attacker’s account.
A recently reported case occurred in 2019, where Binance, cryptocurrency exchange, lost nearly $40 million in Bitcoin due to a sophisticated MitM attack.
How to secure a network
A robust approach to securing your network involves multiple strategies and tools, such as firewalls, VPNs, IPS, and conducting regular network scans, software updates, and employee trainings.
Installing and maintaining firewalls and VPNs
Firewalls function as a primary defense mechanism, acting as a barricade between the internal trusted network and untrusted external networks. For instance, a company might deploy a robust firewall to block any incoming traffic from suspicious IP addresses, keeping unauthorized users at bay.
VPNs are also instrumental in securing data in transit across the network. By creating a secure, encrypted connection between a user’s device and the network, a VPN ensures that any data sent across this connection remains confidential and tamper-proof. An employee working remotely, for instance, could use a VPN to safely access company resources from home.
IPS plays a pivotal role in identifying and neutralizing rapidly spreading threats, such as zero-day or ransomware attacks. These systems monitor network traffic, automatically identifying and mitigating potential threats before they cause significant damage.
A well-implemented IPS might, for example, block traffic from a known malicious IP address, effectively preventing a potential attack.
Regular network scans
Conducting regular network scans is another crucial element of a comprehensive network security strategy. These scans help identify potential vulnerabilities within the network that could be exploited by malicious actors. For instance, a network scan might reveal an outdated piece of software with a known vulnerability, prompting the necessary updates to mitigate this risk.
Keeping software up-to-date is a fundamental aspect of network security. This includes not only the operating systems but also the various applications running on the network. By staying on top of updates, organizations reduce the risk of attacks that exploit older, vulnerable software.
A well-publicized example is the Equifax breach of 2017, which resulted from the company’s failure to patch a known vulnerability in their web application software.
Employees often form the weakest link in the security chain, inadvertently allowing malware or attackers into the system. Regular training and security awareness education can drastically reduce these breaches.
For example, a company might implement a regular training schedule to educate employees on how to identify and respond to phishing attempts, a common method of gaining unauthorized network access.
Leveraging network security tools
Using the right tools is paramount for effective network security. Network security tools can be broadly categorized as follows:
- Network security hardware: This includes devices like firewalls, VPN concentrators, and IPS devices. These devices are physically installed in the network and are crucial for providing perimeter security, secure remote access, and intrusion prevention, respectively.
- Network security software: This encompasses software solutions like antivirus programs, encryption tools, and network scanning and monitoring software. These tools help protect against malware, safeguard sensitive data, and provide visibility into network activity and health.
- Cloud-based network security services: These are security solutions provided as a service over the internet. Examples include cloud-based antivirus solutions, cloud access security brokers (CASBs), and cloud-based DDoS protection services. They provide scalability, lower up-front costs, and up-to-date protection against the latest threats.
Implementing these steps, using the right mix of tools, and fostering a culture of security awareness within the organization are fundamental in fortifying network security.
Network security benefits
Investing in network security is not just a technology decision but a strategic business choice, with numerous direct and indirect benefits. Core advantages range from data protection and regulatory compliance to increased uptime and brand trust.
Safeguarding sensitive data
Firstly, network security is a cornerstone of protecting your organization’s sensitive data. This data could encompass anything from customer personal information and credit card details to proprietary research and financial records. Without robust network security, these valuable assets are at risk of unauthorized access and exploitation.
In the real world, the January 2023 breach of T-Mobile stands as a stark example. In a filing with the US Securities and Exchange Commission, T-Mobile acknowledged that this data breach might result in “significant expenses,” adding to the hefty $350 million settlement they had to pay out to their clients due to a data breach in August 2021.
This series of security mishaps has cost T-Mobile not only a significant financial burden but also a hit to their reputation, as customer confidence was eroded by successive leaks of personal data. Thus, investing in network security is not just about data protection; it’s about preventing potential financial fallout.
Meeting regulatory compliance
In many sectors, such as healthcare, finance, and the public sector, regulatory standards dictate stringent data protection measures. Network security is often central to meeting these standards.
For example, healthcare organizations must comply with the Health Insurance Portability and Accountability Act (HIPAA), which necessitates robust security measures to protect patient data. A failure to comply could result in hefty fines, as well as a loss of trust among patients.
Cyberattacks can cause significant disruptions to your organization’s operations, leading to expensive downtime while the issue is resolved and systems are recovered.
We’ve already mentioned the WannaCry ransomware attack in 2017, which resulted in an estimated downtime cost of $4 billion globally. By preventing such attacks, network security measures help ensure the smooth operation of your business, maintaining productivity and service delivery.
Building brand trust
Finally, as the above story about T-Mobile illustrates, network security is integral to maintaining and improving trust in your brand. In an era when data breaches are regularly in the headlines, customers increasingly value and demand that businesses protect their data. A company known for its robust network security will foster stronger customer relationships and loyalty.
Network security downsides
There are none. Though it might sound glib, the truth is that an unprotected network in today’s internet is simply inviting disaster. If there’s any downside, it’s the cost and personnel required to establish and maintain your network security — but these are nonnegotiable expenses, as necessary as doors on a house or brakes on a car.
Bottom line: Network security is critical
Network security isn’t a cost — it’s an investment in protecting your organization’s assets, ensuring regulatory compliance, minimizing downtime, and enhancing your brand’s reputation. These compelling benefits underscore why network security should be a strategic priority for any forward-thinking company.