An air-gap is a way of layering security on a computer network. By ensuring a computer is not connected to the internet, or connected to any other device which is connected to the internet, a barrier can be created that protects the machine from external influence.

The technology itself is not new. It was previously made popular by facilities that require a heightened level of security, such as military or government organisations that handle classified information.

In the past, communicating between an air-gapped machine and one that is connected to a network required physical storage devices, USB sticks or HSMs for example.

Now, Copper is using encrypted QR codes to sign transactions between an offline (cold) air-gapped computer, and an online (hot) machine connected to the internet.


This added layer of security is particularly suited to digital asset storage solutions which require multiple signatures in order to initiate or complete a transaction.

Copper gives its clients the choice of downloading an encrypted file, to be transferred in a traditional manner, or encrypting the transaction information into a QR code, which can be shown to the cold storage machine.

By using optical air-gapping, clients can mitigate the risk of a compromised physical storage device corrupting their secure offline machine.  It also has the added benefit of increasing the speed at which transactions can be signed and broadcast.

One of the challenges the Copper team encountered when building this solution was the amount of information that needs to be encrypted within the QR image itself. In order to maintain a manageable size, the developers created an image cycling process to display multiple QR codes in rapid succession. The images cycle at a rate that gives the QR code the appearance of being animated.

If you'd like a product demonstration, please get in touch with our sales team.

To learn more about Copper's key sharding approach to crypto custody, please read this article.

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