Implementing these best practices ensures that administrative control over PKI is both secure and resilient, supporting compliance, auditability, and incident response readiness
1. Use Custom Groups—Not Built-in Admin Groups
• Create dedicated PKI admin groups (e.g., PKI_Admins) instead of adding accounts to Enterprise Admins or Domain Admins.
• Assign rights to groups instead of individual users for easier management and audit.
2. Minimize and Separate Administrative Scope
• Separate roles for PKI “service administration” (CA installation, renewal, configuration) and “certificate management” (templates, enrollment, revocation).
• Delegate only the minimum required permissions for each distinct operational role.
• Do not grant blanket control; assign granular permissions based on least privilege.
3. Delegate Rights through the PKI Containers
• Grant permissions to PKI admin groups on the Public Key Services container in Active Directory using AD Sites and Services.
• For CA install/configuration: Allow control of PKI containers such as Certification Authorities, Enrollment Services, AIA, and CDP nodes.
• Protect delegated admin groups from accidental deletion.
4. Control Local CA Administration
• Add PKI admin groups to the local Administrators group on CA servers only, not the entire domain.
• Remove users from local CA admin role after setup or maintenance if not needed regularly.
5. Restrict Template and Enrollment Permissions
• Use security tab on each certificate template to assign “Manage”, “Read”, “Enroll”, or “Autoenroll” rights to designated groups only.
• Remove broad permissions (such as “Authenticated Users” or “Domain Users”) from sensitive templates.vkernel+1
6. Monitor and Audit Delegations
• Perform regular audits (at least annually) of group memberships and delegated permissions.
• Use centralized logging and Alerting for changes to PKI roles, templates, or CA settings.
7. Enforce Role Separation and Tiering
• Use administrative tiering to prevent privilege escalation (e.g., separate OUs or administrative layers for PKI vs. other critical services).
• Isolate CA servers in their own secured Admin Tier to protect against lateral movement.
8. Limit Standing Privileges and Enforce Just-in-Time (JIT)
• Avoid permanent membership in powerful groups. Use JIT access models or privileged access management (PAM) when possible.
9. Document Delegation and Emergency Access
• Document delegated permissions, group purpose, and membership.
• Set procedures for break-glass or emergency PKI admin access—but restrict and log all emergency use.
Summary Table
Practice | Description |
Custom PKI admin groups | Group-based, least-privilege delegation |
Separate service/certificate management | Role separation for different PKI tasks |
Delegate via PKI containers | Assign permissions to AD PKI nodes, not full AD privileges |
Local-only CA admin rights | Limit to CA host; avoid domain-wide rights |
Restrict template/enrollment permissions | Group-based template access; remove broad defaults |
Monitor and audit | Periodic review of delegations and memberships |
Admin tiering and isolation | Dedicated OUs and admin tiers for PKI infrastructure |
Minimize standing privileges | Just-in-time, break-glass, or PAM for exceptional access |
Documentation | Thorough documentation of all delegated rights and processes |