What nullroute is

A signing-only Bitcoin device. It holds keys, displays transactions, and produces signatures. It has no network stack reachable from outside loopback, and it moves data across an air gap by QR code. An SD card transport is planned and not built: nothing in the image mounts removable media.

It is designed to be one signer in a vendor-diverse multisig quorum, not sole custody. The intended deployment is 2-of-3 or 3-of-5 where the other keys live on hardware from other vendors, and nullroute is the signer you can fully audit yourself.

Using it for sole custody of a meaningful amount is a use we do not recommend and have not designed for. There is no secure element (see below), so a single nullroute holding everything is a single physical point of failure.

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