Network Security: An Overview
Ever since the creation of the internet, along with all the good it has brought, came the bad as well. In the age of information technology, an unsecured product is a surefire way to encounter numerous issues. A company that creates a product must ensure that both the software and network security features are as robust as possible.
In the previous article, we discussed application security; however, it is never complete without clear network safeguards to serve as a frontline defense against malicious users trying to exploit the system. But what is network security, and what are some of the methods used to protect systems?
What Is Network Security?
Network security is the practice of preventing and protecting against unauthorized intrusions into any large corporate or smaller home network. It complements endpoint security, which focuses on individual devices rather than their interactions with each other.
The SysAdmin, Audit, Network, and Security Institute (SANS) — a private U.S. for-profit company founded in 1989 specializing in information security, cybersecurity training, and certifications — defines network security as:
“Network security is the process of taking physical and software preventative measures to protect the underlying networking infrastructure from unauthorized access, misuse, malfunction, destruction, or improper disclosure, thereby creating a secure platform for computers, users, and programs to perform their permitted critical functions within a secure environment.”
To rephrase it: network security consists of methods to prevent unauthorized users from accessing your hardware. Ideally, someone cannot hack into your computer remotely if they cannot connect to it via the network.
Network Security Basics
Definitions are easy to understand as a starting point, but how does one implement that vision in practice? Let's discuss some of the network security basics. Although there are numerous different perspectives, three major aspects always stand out:
- Protection: Correct configuration of the system and network.
- Detection: Ability to identify changes in configuration or notice suspicious network activity.
- Reaction: Quickly identifying and responding to problems to return to a safe state and maintain service availability.
It is universally accepted that all three must be covered when securing a network. Overreliance on one will lead to weaknesses in the others and leave the system vulnerable to exploitation.
The best way to view network security is not as a single line of defense — where if breached, everything collapses — but rather as a battlefield. Even if an attacker penetrates one area, the threat can still be detected, isolated, and removed without letting them compromise the entire system.
Cloud Services and Network Security
Cybersecurity is expensive. It requires significant funding, a trained team of professionals, licenses, and more. As a result, many companies have started outsourcing their computing to cloud service providers, creating hybrid infrastructures. Even this isn't easy: these infrastructures are often self-contained networks, consisting of either physical machines or multiple virtual machines running on the same server.
To tackle security issues, many cloud service providers have developed centralized security control policies on their platforms. However, these systems don't always align with the policies of the companies hiring their services, creating additional workloads for network security professionals.
Common Methodologies
Network security combines multiple layers of defense. Each layer implements policies and controls to regulate who gets access and who gets blocked.
Cisco, a multinational technology conglomerate specializing in IT, networking, and cybersecurity solutions, lists several types of network security:
Firewalls: Act as barriers between your trusted internal network and the outside world. Firewalls regulate which applications have access rights and can be implemented via hardware or software. Categories include:
- Network firewalls
- Next-generation firewalls
- Web application firewalls
- Database firewalls
- Unified threat management
- Cloud firewalls
- Container firewalls
- Network segregation firewalls
Email Security: Email is a major gateway for security breaches. Attackers use social engineering to craft sophisticated phishing campaigns, leading recipients to bogus sites or infecting their systems. Email security applications block incoming attacks and control outbound messages to safeguard sensitive information.
Anti-Virus and Anti-Malware Software: Protect systems from malicious software, including viruses, worms, Trojans, ransomware, spyware, and more. Malware often remains dormant until triggered, sometimes days, months, or even years later.
Network Segmentation: Categorizes network traffic into segments, making enforcement of security policies easier — "divide and conquer."
Access Control: Limits user privileges. Network Access Control (NAC) regulates which devices can connect and what access rights they receive.
Application Security: Protects the applications themselves, as any software can contain vulnerabilities.
Behavioral Analysis: Detects anomalies by understanding normal behavior through extensive logging and monitoring.
Data Loss Prevention (DLP): Ensures that sensitive information is not sent outside the network by blocking unauthorized uploads, forwarding, or printing.
Intrusion Prevention Systems (IPS): Scans network traffic for attacks and blocks them upon detection. Cisco’s Next-Generation IPS (NGIPS) uses global threat intelligence to not only block attackers but also monitor their movements inside the system.
Mobile Device Security: As mobile devices increasingly handle banking, shopping, and other critical activities, they have become prime targets. Mobile device security (MDS) is now a vital part of network protection.
Security Information and Event Management (SIEM): Helps security teams identify and respond to threats by aggregating and analyzing security data.
Virtual Private Networks (VPNs): Encrypt connections between an endpoint and a network. Even if intercepted, the data remains unreadable to attackers. VPNs also make tracking individual connections more difficult.
Web Security Solutions: Control corporate staff’s internet access, blocking malicious websites and threats.
Wireless Security: Wireless networks are much less secure than wired ones. Since wireless access can be attempted from nearby locations, it's critical to use proper protections and avoid conducting sensitive activities over public Wi-Fi networks.
Additionally, security professionals use various tools to monitor network activity, including:
- Packet sniffers: Provide deep insight into network traffic.
- Vulnerability scanners: Tools like Nessus.
- Intrusion detection/prevention software: Such as Snort.
- Penetration testing tools: Simulate attacks to find weaknesses.
Conclusion
Network security is an integral part of system protection. Despite the expense and intensity required, it is essential.
However, not everyone needs "Pentagon-level" security. A small business that doesn't manage sensitive customer data doesn’t need 10 security guards, a blast-proof server room door, and 24/7 monitoring.
Security measures should match the service being provided. Correct assessment of needs and risks is crucial. Security budgets are typically established after an extensive threat assessment, which can be performed either internally or by third-party professionals.
