How to Become a Cybersecurity Specialist
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Defense in Depth

What is Defense in Depth (DiD)?

A strategy is known as Defense in Depth (DiD) in the context of information security is one that makes use of several different security approaches and controls. These security protocols are typically implemented in layers across the entire computer and system network to protect the integrity, confidentiality, and availability of the network and its data and to prevent unauthorized access.

The fact that there is no single, all-encompassing solution to mitigate against all cyber threats must be acknowledged. In practice, however, employing a variety of security approaches gives the impression of comprehensive protection against a wide range of current and emerging threats. DiD also aids in the incorporation of redundancy if one mechanism fails. Put another way, a successful DiD approach improves computer and network security by protecting against multiple attack vectors.

Key Takeaways

  • In cyber security, Defense in Depth (DiD) refers to the strategy of employing a series of security approaches and controls to provide a sense of comprehensive protection against a wide variety of cyberattacks.
  • Organizations can use a layered approach to information security to protect data at all levels of the information technology structure.
  • Defense in depth is achieved by incorporating several different defense mechanisms, such as firewalls, integrity auditing solutions, data encryption, malware scanners, and intrusion detection systems, into a single defense strategy. In addition to security policies and best practices, a successful DiD security strategy should include several other components.
  • Because it increases network security redundancy, Defense in Depth is important because it helps to avoid the occurrence of single points of failure.

    How Defense in Depth Works

Organizations can use a layered approach to information security to protect data at all levels of the information technology structure. Defense in Depth significantly improves the security profile of an entity, from the single computer accessing the organizational network to the multiple user enterprise’s wide area networks, at all levels of the organization’s security profile (WAN). There is no single security layer that can protect the entire corporate network in its entirety. Because of the gaps created by a single security solution, hackers can exploit vulnerabilities in a variety of different areas of a network. Defense in Depth is a security strategy that employs a variety of controls, such as firewalls, integrity auditing solutions, data encryption, malware scanners, and intrusion detection systems, to effectively close security gaps.

Best practices, tools, and policies for Defense in Depth are available here.
Defense-in-depth security strategies incorporate (but are not limited to) the following security tools, policies, and best practices to provide an effective defence against threats:

Defense in Depth Best Practices, Tools, and Policies

These software or hardware tools manage network traffic by allowing or denying network traffic based on security rules and policies that have been previously defined. In a DiD framework, the rules include whitelisting and blacklisting IP addresses based on the security situation, respectively. Application-specific firewalls, such as secure email gateways and Web Application Firewalls, are also included in the DiD suite of features (WAF). These tools are equipped with features that allow them to detect malicious activity directed at a particular application.

Systems that detect or prevent intrusions (IDS/IPS) are also available.
An intrusion detection system (IDS) notifies users when malicious network traffic is detected, whereas an intrusion prevention system (IPS) attempts to prevent system compromise. These security solutions identify attacks based on signatures of malicious activity that have previously been identified.

Monitoring and responding to endpoints (number three) (EDR)
EDR software is installed on client systems, such as mobile phones or personal computers, to provide emergency response capabilities. Using rulesets, the software improves data security by executing actions such as antivirus detection, alerting, analyzing, threat triaging, intelligence gathering, and protection.

Network segmentation is the fourth step.
Network segmentation is the process of dividing networks into sub-networks that are designed to meet specific business requirements. Management, finance, human resources, and operations are just a few of the organizational functions that have multiple sub-networks each with its specific functions. Segmentation is accomplished within a DiD structure through the use of firewall rules and network switch configuration.

5. The Principle of Least Privilege (also known as the Least Privilege Principle)
The principle of least privilege necessitates the implementation of technical and policy controls to ensure that users, processes, and systems have access to only the resources they require to perform their assigned functions.

Patch Management is the sixth point to mention.
When it comes to information and computer security, it is critical to keep up with the latest developments. As a result, patch management is integrated into DiD frameworks when it comes to applying updates to software, middleware, and plugins. Because of the patches, DiD security protocols are now able to address vulnerabilities that could allow unauthorized access to occur.

Why Does Defense in Depth Matter?

As previously stated, there is no silver bullet for cybersecurity challenges. Defense in-depth, on the other hand, is important because it increases network security redundancy, thereby preventing the occurrence of single points of failure. The strategy increases the amount of time and complexity that is required to successfully compromise the entire network. Indeed, distributed denial of service (DDoS) security frameworks makes it more difficult for cybercriminals to achieve their goal while also increasing the likelihood that a potential attack will be detected and prevented in time.

DiD approaches are frequently used to protect valuable equipment and material assets when physical security frameworks are being put in place to protect them. During elections, for example, officials implement a series of locks, security cameras, and custody logs to safeguard the physical election environment. The use of records, cameras, and locks helps to ensure that election equipment and infrastructure are properly protected. Another example is the banking industry, where ballistic glass, vaults, and security cameras are all used to protect personnel and assets against theft and vandalism.

DiD Control Areas

The underlying concept of DiD entails the ability to defend a system against a wide range of attacks by employing a variety of different independent approaches. Using a layering strategy that incorporates multiple levels of control, this comprehensive security approach can be implemented. The DiD framework tools can be divided into three categories: physical, technical, and administrative. Physical tools include:

Controls that are physical
The physical aspects of DiD security control include the tools and equipment that are used to restrict physical access to the facility. CCTV systems, guards, door access control, and fences are all examples of security measures.

Controls that are technical
Technical controls are software and hardware that are used to protect information technology systems and resources within a DiD framework. Authentication, biometric readers, firewalls, intrusion prevention systems/intrusion detection systems, virtual private networks, and disc encryption are all examples. The primary goal of technical controls is to restrict access to the contents of a computer system.

Controls on an administrative level
Administrative controls are established by the procedures and policies of an organization. Their responsibility is to ensure that appropriate guidance on information technology security and compliance issues is always available. Hiring practices, security requirements, and data handling procedures are examples of administrative DiD measures that may be implemented.

Common DiD Methods

More than one of the layers detailed below can be implemented to create a comprehensive DiD security framework, as shown in the following example:

Security of the system and applications
These standards and practices are incorporated into this layer, and they include:

  • Software that protects against viruses and malware
  • Encryption
  • Techniques for sandboxing
  • Intrusion Detection and Prevention Systems
  • Passwords that are hashed
  • Scanners for vulnerabilities
  • Keeping track of and auditing security awareness programs
  • Authentication with multiple factors
  • Controlling who has access to what information
  • Network security is a concern for many people.
  • This layer is responsible for integration.

Virtual private networks (VPNs) and firewalls are two types of virtual private networks.
Protection on a physical level
The following are examples of standard tools and practices: