What is defense-in-depth?
Defense-in-depth is a cybersecurity strategy that relies on multiple layers of security controls to protect your systems, data, and users from threats.
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The logic behind using multiple layers of defense has been around since ancient warfare times. If you rely on a single defensive mechanism, and it fails, you are exposed. Extra layers and contingencies of defense-in-depth allow you to mitigate risks much more easily in a best case scenario, and make it very hard and time consuming for malicious actors to break your defenses in a worst case scenario.
Defense-in-depth in Microsoft 365 refers to a multi-layered security strategy designed to protect an organization's data, users, and infrastructure from threats. Instead of relying on a single security measure, defense-in-depth implements multiple overlapping security controls to reduce risk, detect potential breaches, and minimize damage in case of an attack.
Microsoft 365 defense-in-depth
For Microsoft 365 admins, this approach includes:
- Identity and access management (e.g., Entra ID, multi-factor authentication) to protect user accounts.
- Threat protection (e.g., Microsoft Defender for Office 365) to detect and block malware, phishing, and other cyber threats.
- Data protection (e.g., sensitivity labels, encryption, and data loss prevention) to safeguard sensitive information.
- Monitoring and auditing (e.g., Microsoft Purview, audit logs) to detect suspicious activities and enforce compliance.
