FREE ARCHITECT'S GUIDE
Data Diodes vs. Unidirectional Gateways
The architect's decision guide to one-way OT security. Inside: the real difference between data diodes and unidirectional gateways, how to spot vendors that overclaim "one-way" protection, and how to give IT real-time operational data with no path back into your OT network.
This guide will provide you with a clear, practical breakdown to help you choose the right one-way architecture and defend the decision to your team:
- The real technical and practical differences between the two and a clear framework for choosing the right fit for your OT network.
- Why every firewall connection is ultimately two-way, and what kinds of attacks hardware-enforced protection stops that software cannot.
- How to tell real hardware-enforced unidirectionality from “unidirectional firewalls” and all-software products that always leave attack paths open.
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What's inside the guide?
Inside this free guide, you’ll get a clear, practical breakdown that helps you choose the right one-way architecture -
and defend the decision to your team:
Diodes vs. gateways - which one fits
The real technical and practical differences between the two - and a clear framework for choosing the right fit for your OT network.
Verify true one-way security
How to tell real hardware-enforced unidirectionality from “unidirectional firewalls” and all-software products that quietly leave a way back in.
Why firewalls fall short
Why every firewall connection is ultimately two-way, and what hardware-enforced protection stops that software cannot.
Live data to IT, no attack path
How gateways replicate historians, SQL, Modbus and OPC so IT gets real-time operational data with no route back into OT.
Compliance, mapped
How hardware-enforced, one-way protection supports IEC 62443, NERC CIP and NIST SP 800-82 requirements.
Proven in the field
Real world deployments - with 100% security, full data visibility, and simpler regulatory compliance.
FAQs
What OT and security teams ask most before choosing a one-way security architecture.
What is a data diode?
A data diode is a hardware device that physically enforces one-way data flow: information can leave your OT network, but nothing can travel back in through the connection. No online attack can reach your OT systems through that path.
What's the difference between a data diode and a unidirectional gateway?
The data diode is the hardware. It is physically able to send information in only one direction. A unidirectional gateway adds software that replicates OT servers, databases, and applications to the IT side, making the integration both safe and seamless. The guide breaks this down in detail.
Are unidirectional gateways more secure than firewalls?
Yes. Firewalls are software that can be misconfigured or breached; unidirectional gateways enforce one-way data flow in hardware, so there is no path for an attacker to traverse into the protected network through a unidirectional gateway.
Do unidirectional gateways help with IEC 62443 and NERC CIP compliance?
They directly support the network-segmentation and boundary-protection requirements in standards like IEC 62443 and NERC CIP. The guide maps the architecture to common regulatory requirements.
Which industries use unidirectional gateways?
Power generation and utilities, oil & gas, water, manufacturing, data centers, and rail — anywhere an OT network needs to share data without exposing itself to external threats.