Zero Trust
Zero Trust is a security model built on the principle that no user, device, or network should be trusted by default. Even if you are inside the corporate perimeter, every access request must be verified.
The Problem with Traditional Security
Traditional network security operates on a "castle and moat" model: once you are inside the network, you are trusted. Firewalls keep outsiders out, but anyone or anything inside can freely move between systems. This approach has several weaknesses:
- Assumes internal safety: A compromised device inside the network can access any resource without challenge
- Broad access by default: Users and services are granted wide permissions that are rarely revoked
- Difficult to audit: With implicit trust, it is hard to track who accessed what, when, and from where
How Zero Trust Works
Zero Trust replaces implicit trust with continuous verification. Every request to access a resource must prove its identity and authorization before being granted, no matter the source. The model rests on three core principles:
- Never trust, always verify: Every connection is authenticated and authorized before access is granted
- Least privilege access: Users and devices receive only the minimum permissions needed to perform their task
- Assume breach: Security design assumes that an attacker is already present, so every layer must be protected independently
Zero Trust in Industrial Automation
Industrial environments face unique challenges that make Zero Trust particularly important:
- OT/IT convergence: Operational technology (PLCs, HMIs, sensors) is increasingly connected to IT networks and the internet, expanding the attack surface
- Remote access needs: Engineers, vendors, and operators require secure access to devices from anywhere, which traditional perimeter security cannot provide safely
- Long-lived assets: Industrial equipment often remains in service for decades, making it impractical to constantly patch or update every component
Zero Trust addresses these challenges by ensuring that remote access to industrial devices is granted only after verification, with the minimum permissions required and full audit logging.
Zero Trust on Mutexer
The Mutexer platform implements Zero Trust through its Horizon service, which provides secure, policy-driven access to internal services without exposing them directly to the internet. Horizon enforces Zero Trust by default: every circuit starts with no implicit access, and nothing is reachable until an access policy is explicitly configured.
For details on how Zero Trust is implemented in the platform, see Horizon.