Bitcoin Forum

Are there any OpenSource projects supposed to create hardware Trezor-like device based on widely available Atmega devices or Raspberry Pi?
I have seen ECDSA implementation for Arduino, but it is very little to start with. Yes, Raspberry Pi may be a good option, it is an actually full-featured computer, but this makes it opened to a number of security flaws, bugs and unknown breaches.

Your opinion?

I think the raspberry pi is good for a cold storage device.
If you download the wallet software on an online computer and an offline computer (the raspberry pi). Then sign transactions on the raspberry pi with inputs you can load from the online software and the broadcast the signed transaction on the online computer.

Plugging a raspberry pi into a computer means you lose what you were using the pi for as you can just access the drives on the pi almost as easily as you can your PC.

Well, Raspberry Pi is too smart, because it has Wi-Fi module.

Do we need Opensource Hardware wallet at all?

Trezor did have the Raspberry Pi "shield" at one point... An add-on circuit board with Trezor-like OLED screen and two little hardware buttons...

It would appear it never caught on and people just bought a Trezor instead :P

I think the fact that a Pi has some much attack surface would make it difficult to lock down as a hardware wallet... You'd need to remove so much (ethernet, wifi etc) and no doubt have some custom USB drivers or something to prevent data being "leaked" from it...

Still, I've seen Pi full nodes with attached HDDs and little screens etc... So maybe useful as an "airgapped" offline wallet?