Damus
BitRoot profile picture
BitRoot
@BitRoot
I have a security question that has been bugging me.

When a wallet broadcasts a Bitcoin transaction, we trust it's only sending the signature and transaction data. But how can we be certain that fragments of the private key aren't being secretly embedded in the broadcast over time?

For example, could a malicious hardware wallet manufacturer design a device that, after many transactions, allows them to reassemble the bits and know the private key?

Has anyone ever done a public test where the same seed phrase is used on different hardware wallets (like @Coinkite @DETERMINISTIC OPTIMISM ๐ŸŒž, Trezor @karliatto, @Keystone) to sign the exact same transaction?

If the resulting signatures are identical, would that be definitive proof that both devices are performing the standard, non-corrupted signing process?

62โค๏ธ3๐Ÿค™1
Dikaios1517 · 1w
Yes, and multi-sig using signing devices from different manufacturers is one of the main ways to protect against this.
DETERMINISTIC OPTIMISM ๐ŸŒž · 1w
If you use deterministic k value and reproducible builds that's not a concern. That's the method core and COLDCARD use
karliatto · 1w
There are different ways to solve this. In my opinion, the first is that the device firmware must be open source so everyone can verify it and reproduce builds, ensuring users get the correct firmware. Without this, any of the other solutions are probably worthless. In addition, Trezor firmware ge...
BitRoot · 1w
Cool! Many thanks nostr:nprofile1qqstwf6d9r37nqalwgxmfd9p9gclt3l0yc3jp5zuyhkfqjy6extz3jcpz9mhxue69uhkummnw3ezumrpdejz7q2uwaehxw309ac8ymmc0yhxummnw3ez6un9d3shjtnpwpcz7vehvs6xxvenvgmxgep3x9jnzdf4xd3nxephv9skycn9vsergcnrv5ukzdfsve3nwvnxxucngd35vsenje3cvc6nycm98qekyetrvcuqnnucu2 nostr:nprofile1qqsyu9me...