Update security-operations-introduction.md

Author: janicericketts

articles/active-directory/fundamentals/security-operations-introduction.md

@@ -19,7 +19,7 @@ ms.collection: M365-identity-device-management
 
 # Azure Active Directory security operations guide
 
-Microsoft has a successful and proven approach to [Zero Trust security](https://aka.ms/Zero-Trust) using [Defense in Depth](https://us-cert.cisa.gov/bsi/articles/knowledge/principles/defense-in-depth) principles that use identity as a control plane. Organizations continue to embrace a hybrid workload world for scale, cost savings, and security. Azure Active Directory (Azure AD) plays a pivotal role in your strategy for identity management. Recently, news surrounding identity and security compromise has increasingly prompted enterprise IT to consider their identity security posture as a measurement of defensive security success.
+Microsoft has a successful and proven approach to [Zero Trust security](https://aka.ms/Zero-Trust) using [Defense in Depth](https://www.cisa.gov/sites/default/files/recommended_practices/NCCIC_ICS-CERT_Defense_in_Depth_2016_S508C.pdf) principles that use identity as a control plane. Organizations continue to embrace a hybrid workload world for scale, cost savings, and security. Azure Active Directory (Azure AD) plays a pivotal role in your strategy for identity management. Recently, news surrounding identity and security compromise has increasingly prompted enterprise IT to consider their identity security posture as a measurement of defensive security success.
 
 Increasingly, organizations must embrace a mixture of on-premises and cloud applications, which users access with both on–premises and cloud-only accounts. Managing users, applications, and devices both on-premises and in the cloud poses challenging scenarios.