Companion app.
The side that talks to the network can’t spend a thing.
- Holds a viewing key only. Never a spending key.
- Builds the payment, proves it, broadcasts what the signer signed.
- Shows the same address rows as the device, so you can compare.
Case.
Made to be opened and compared with what’s published.
- 58 × 96.5 × 9 mm, two side buttons, 0.7 mm cover glass.
- Held with screws, not glue. Open it and look.
- Left rejects, right approves. Hold both for 1.5 s to sign.
E-ink panel.
What you approve is drawn here, not on your computer.
- Amount, recipient, fee and memo, shown before you hold to sign.
- The recipient in numbered rows of four-character groups, matching the app.
- An added board could read this screen, seed words included. Firmware can’t tell.
Firmware.
It checks the payment itself instead of taking your computer’s word.
- Checks every amount and output against its commitments, then computes the ZIP-244 sighash itself.
- For a payment, only signatures go back over USB. No command sends the seed.
- Reproducible builds: match the binary on your device to the source.
Schematic.
Every part and every connection, published.
- Drawn in KiCad, starting from the open Dabao board files.
- Chip, panel driver, USB-C, two switches. No battery, no radio.
- Published with the board layout, so the two can be checked against each other.
PCB.
A layout you can hold up against the board itself.
- Layout files and photos of the inside, published to compare.
- Setup asks you to inspect the board before the device makes a seed.
Chip.
The signer runs on a security chip you can inspect.
- Secure-element features on the signing die: TRNG, glitch sensors, security mesh.
- No separate secure element: keys and RedPallas signing share one chip.
- Open bootloader, mostly open RTL, in a package you can inspect by infrared.
Seven layers. None of them should be hidden.