I'm curious: can you run a Bitbox02 signer to sign on a computer which itself is airgapped? I get dark skippy makes the direct airgap an issue, but curious if the additional device being airgapped may...
Good question. Yes, you can connect a BitBox02 via USB to a computer that is kept offline and move PSBTs between that machine and an online broadcaster.
But the offline computer alone doesn’t solve Dark Skippy. A malicious signer could still hide seed data inside the signatures, which becomes public when the transaction is eventually broadcast.
The key protection is BitBox02’s Anti-Klepto protocol. The host contributes randomness to the nonce and verifies that the signer did not manipulate it. It runs automatically with BitBoxApp and is also supported through HWI with Sparrow and Electrum.
So the offline computer adds another layer of isolation, while Anti-Klepto is the actual Dark Skippy mitigation. Multisig can still provide additional defense in depth.
https://blog.bitbox.swiss/en/how-almost-all-hardware-wallets-can-steal-your-seed/
But the offline computer alone doesn’t solve Dark Skippy. A malicious signer could still hide seed data inside the signatures, which becomes public when the transaction is eventually broadcast.
The key protection is BitBox02’s Anti-Klepto protocol. The host contributes randomness to the nonce and verifies that the signer did not manipulate it. It runs automatically with BitBoxApp and is also supported through HWI with Sparrow and Electrum.
So the offline computer adds another layer of isolation, while Anti-Klepto is the actual Dark Skippy mitigation. Multisig can still provide additional defense in depth.
https://blog.bitbox.swiss/en/how-almost-all-hardware-wallets-can-steal-your-seed/