securing-historian-server-in-ot-environment

# Securing Historian Server in OT Environment ## When to Use - When deploying a new historian server in an OT environment and configuring it securely from the start - When hardening an existing historian after a security assessment identified it as a high-risk target - When designing historian data replication architecture through a DMZ for IT access to process data - When implementing access controls to prevent unauthorized modification of historical process data - When investigating suspected historian compromise or data integrity issues **Do not use** for IT-only database security without OT data (see general database hardening), for real-time SCADA data transmission security (see detecting-attacks-on-scada-systems), or for historian selection and sizing decisions. ## Prerequisites - Historian platform (OSIsoft PI, Honeywell PHD, GE Proficy, AVEVA Historian) installed and operational - Network segmentation with historian placed in Level 3 (Site Operations) per Purdue Model - Understanding of data flows: field devices -> PLCs -> OPC servers -> historian - Access to historian administration credentials - DMZ infrastructure for IT-facing data replication ## Workflow ### Step 1: Audit Current Historian Security Configuration Evaluate the current security posture of the historian server including network exposure, authentication, and access controls. ```python #!/usr/bin/env python3 """Historian Security Audit Tool. Evaluates the security configuration of process hist...