Cybercriminals may be skilled, but they aren't invincible. Every successful attack is due to the absence or inadequacy of cybersecurity. If you could tighten your security, you would keep intruders out of your network.

You can match the tenacity and perseverance of threat actors with a defense in depth strategy, resisting them until they get exhausted. Find out how defense in depth works, its benefits, and how you can implement it.

What Is Defense in Depth?

Defensive in depth (DiD) is a process of combining both human and technical resources to create multiple security layers to protect your data and other digital assets. This is in contrast with securing your network with a single security mechanism. In the latter situation, if a threat actor identifies and exploits a vulnerability in that defense mechanism, they would gain access to your network.

It's a different ball game when you have various defenses, since cybercriminals will face several barriers even after exploiting certain vulnerabilities.

Like most cybersecurity strategies, DiD originated from the military. When an opponent strikes, instead of responding immediately with a strong action, you make a small move to push them back while you gain more intel on the best ways to eradicate them.

Although DiD takes a cue from the military, its application in cybersecurity differs. Instead of stalling an intruder, you create multiple defense layers to resist their attacks.

How Does Defense in Depth Work?

Defense in depth is also known as the castle approach in some quarters. This stems from its similarities with the layered defenses in the medieval castle. Barriers such as drawbridges, towers, and moats are placed in front of the castle to shield it from the enemy. The enemy must conquer them before getting to the castle.

There are three components of a DiD cybersecurity strategy: technical, administrative, and physical controls.

Technical Controls

The goal of technical controls is to secure the resources in your network. They involve the use of advanced software and hardware such as firewalls, encryption, and intrusion detection systems to secure your data.

Technical controls manage access and prevent unauthorized users from entering your system. These tools play a critical role in DiD. But for them, cybercriminals can bypass entry protocols without any barrier. They also help you secure data at rest and data in transit.

Administrative Controls

Administrative controls refer to user-facing measures you have in place to secure your digital assets. It requires you to enact policies guiding user behaviors and interactions to avoid actions that can endanger or expose your data to threats.

Administrative controls help prevent insider threats. Users on your network can either intentionally or unintentionally exhibit behaviors that put your network at risk of attacks. If administrative-based threats or attacks arise, the controls in this area will stop them in their tracks.

Physical Controls

Physical controls refer to the measures you use to prevent intruders from gaining on-premise access to your network. These techniques include the use of biometric systems, digital locks, intrusion detection sensors, and surveillance cameras to secure your data from physical encroachment.

How to Implement Defense in Depth Strategy

Audit Your Network

Securing your network effectively begins with identifying the various applications in your system, how they function, and their vulnerabilities. To do this, you need to conduct a thorough audit to understand the operational details, especially as it pertains to security.

Classify and Prioritize Critical Data

Prioritizing data helps you identify your most critical data and give them the level of attention they deserve. Data classification precedes prioritization. Create clear metrics for classification and group similar data into the same category to manage your security resources efficiently.

Implement Multiple Firewalls

Firewalls are an active part of a defense in depth strategy—they sieve incoming and outgoing traffic to your network, checking for anomalies. Implementing firewalls requires you to outline perimeters for traffic entry eligibility. Any traffic that falls shorts of those perimeters will face a barrier.

With multiple firewalls in a DiD strategy, attack vectors will face multiple barriers even if they bypass some vulnerabilities.

Develop Endpoint Security

Since endpoints are the entry points to networks, attackers target them to make their way through. Adding endpoint security in your DiD strategy makes your access points more secure. It gets even better with endpoint detection and response (EDR), a system that detects threats in real-time and launches defenses immediately.

4 Benefits of Defense in Depth

The element of surprise is an advantage in battle, one that you get when you implement a defense in dept strategy. Just when cybercriminals think they have bypassed your security barriers, they face multiple hindrances along the way.

Here are some of the benefits of a DiD security framework.

1. Active Isolated Security Zones

Isolated security zones refer to various independent security mechanisms in one network. Instead of these techniques being connected, they function separately as individual entities. This means that, even when an attacker compromises one zone, other zones can still function because they are independent.

Defense in depth offers you isolated security systems that make your network more secure. An intruder might think they have beaten you to it once they take down a particular security defense, but they soon realize that there are other active defenses.

2. Resistance Against Multiple Threats

No matter how accurate you are in predicting cyber threats and attacks, you may not capture the entire angles of an attack. Intruders can change their tactics at any point to bypass the security defenses they foresee.

Defense in depth helps you create various defenses to tackle different threat vectors. Instead of focusing on one area and then losing if you are wrong, your multiple defenses will secure even areas you wouldn’t pay attention to ordinarily.

3. Monitoring Network Activities

Many cyberattacks are successful due to the absence of effective monitoring to detect suspicious activities within systems. Contrary to the misconception that DiD is all about defending threat vectors, it also detects emerging threats and stops them before they escalate. And this is possible with the use of threat monitoring and prevention tools.

4. Enforcing Data Privacy

Ensuring the highest level of data privacy is a necessity in the highly volatile cyberspace. Defense in depth is one of the few cybersecurity strategies that can protect data both at rest and in transit, which it does through data hashing and encryption.

Data backup, a critical function of a DiD strategy, enhances data privacy. If you suffer a data breach or attack, your DiD solution can help you restore your data via its backup feature.

Create Robust Security With a Defense in Depth Strategy

To attain the most effective cybersecurity framework, you either go big or go home. Defense in depth leaves no stone unturned by requiring you to create multiple defenses to secure your data.

Cybercriminals don't stop until they achieve their goals. You make it too easy for them if you have just one or two defenses. With a DiD strategy, you create multiple systems to protect your territory even if they are redundant.