How do you use security domains and controls in your network?

1 What are security domains?

A security domain is a logical grouping of network resources, such as devices, servers, applications, data, or users, that share common security requirements and trust levels. For example, you might have a security domain for your internal network, another one for your public-facing web servers, and another one for your remote workers. Security domains help you isolate and protect your network segments from unauthorized access, attacks, or breaches.

2 What are security controls?

A security control is a measure or mechanism that you apply to a security domain to reduce its risk exposure and ensure its compliance with your security policies and standards. Security controls can be classified into three types: physical, technical, and administrative. Physical controls are the tangible barriers or devices that prevent or deter unauthorized physical access to your network resources, such as locks, fences, cameras, or alarms. Technical controls are the software or hardware tools that prevent or detect unauthorized logical access to your network resources, such as firewalls, encryption, authentication, or antivirus. Administrative controls are the policies, procedures, or practices that govern the behavior and actions of your network users, such as training, awareness, audits, or backups.

3 How to design security domains?

The design of your security domains depends on various factors, including your network topology, business objectives, security requirements, and regulatory compliance. To guide you, some general principles to consider are to identify and classify your network resources according to their sensitivity, criticality, and function; group resources into security domains based on their similarity and compatibility of security requirements and trust levels; define the boundaries and interfaces of your security domains, and document their roles and responsibilities; apply the principle of least privilege, granting the minimum level of access and permissions necessary for network users to perform their tasks; and apply the principle of separation of duties, distributing tasks and responsibilities among different network users or roles to prevent conflicts of interest or abuse of power.

4 How to implement security controls?

The implementation of your security controls depends on the specific risks and threats in your network environment, as well as your security policies and standards. To ensure optimal security, you should conduct a risk assessment to identify and prioritize the vulnerabilities and threats that affect your security domains, and select the appropriate security controls based on their risk level and cost-effectiveness. You can use frameworks such as NIST SP 800-53 or ISO 27001 to guide you in choosing the best practices and controls for your network security. Additionally, it's important to monitor and evaluate the performance and effectiveness of your security controls, making adjustments as needed. Lastly, make sure to review and update your security policies and standards regularly, communicating them across all network users and stakeholders.

5 How to benefit from security domains and controls?

Using security domains and controls in your network can bring many benefits, such as improving your security posture and resilience, enhancing your network performance and efficiency, and achieving compliance and governance. This will reduce your attack surface, detect and prevent security incidents, minimize the damage and recovery time in case of a breach, optimize network resources, reduce network congestion and latency, enable faster data transmission and processing, meet legal and regulatory requirements, and demonstrate accountability and transparency to customers, partners, and authorities.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?