What is a data diode?

Simply put - 'A data diode is a cybersecurity device that ensures data can only flow in one direction'

Simple Data Diode


Data diodes are generally hardware based having a transmit side and a receive side connected via a unidirectional fibre optic transmission path. Composed of only a single fibre strand with a light source at one end and an optical receiver at the other this ensures there's no opportunity for data to travel in the opposing direction.

Their use and deployment are best understood when examined alongside the 3 tenets of cybersecurity :-

  • Confidentiality - keeping sensitive information private
  • Integrity - ensuring the consistency of data over its lifetime
  • Availability - allowing data to be freely available to authorised users

Data diodes facilitate cybersecurity by allowing networks of differing security levels to be connected in a secure manner. Data diodes safeguard secrets and secure assets. When safeguarding secrets confidentiality is maintained. When securing assets the priority is integrity and availability.

Depending on the desired design goals data diodes are generally deployed in one of two ways.

1. Receive only data diode - Safeguarding secrets & maintaining confidentiality

When deployed in a receive only manner data is only permitted into the high security environment. Due to the inherent design of the diode no confidential data can ever exit this network. This design is most commonly used to protect intellectual property and classified information.

Receive only data diode


2. Transmit only data diode – Securing assets, ensuring data integrity & availability

The transmit only deployment allows data out of a high security environment. This design makes data available to users downstream while at the same time protecting the assets that generated it from external attack

Transmit only data diode


Data diodes have proven utility across a wide variety of industry sectors, securing information and protecting critical assets. Since the mid 90's Lanode have been providing a wide range of diode installations to both Government and commercial organisations. Our technical team are happy to discuss your requirements and can advise on how best to integrate a diode solution into your network.

More information...

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