Hardware Bitcoin Wallet

[Come-from-Beyond]

Cheap display like http://www.kx-e.com/upload/gift/2010121617271237333.jpg should be enough.

[BkkCoins]

Cheap display like http://www.kx-e.com/upload/gift/2010121617271237333.jpg should be enough.

I was thinking more along this lines,

http://www.ebay.com/itm/84-48-LCD-Module-White-backlight-adapter-PCB-for-Nokia-5110-Arduino-/170817974147?pt=LH_DefaultDomain_0&hash=item27c58b6f83

I know these can be got in qty with only a single line and for less than $1 each, but I no longer have the details on them. It was years ago. I bought the kind in this ebay post for about $3 in Bangkok around 5 years ago, in qty 2-3. So no doubt they are readily available in China for much less. These LCD displays usually have a chip mounted on the glass and can be controlled by any micro controller thru either a serial or 4/8 bit port.

[ralree]

I made a little AVR-powered LCD badge starting with a schematic and going all the way to home-etched board about a year and a half ago.  Maybe I could get a chip with some more horsepower and write some code to make it into a project like this.  Some have suggested using a regular USB key to move between your secure PC and your internet PC.  I don't like the idea of using USB for this because of the possibility of infection:

http://www.tomshardware.com/news/usb-flash-virus-secure,6564.html

If you plug in your USB key to an infected PC connected to the internet, and it's infected, then you plug it into your "vault" PC, the secure PC could also be infected.  If the virus author is clever enough, your private key could be compromised when you plug the key back into the internet PC.  Why not do all of this without USB?  I wonder if a serial interface could be devised that would allow you to send in JSON of a requested transaction (like {address, amount}), have you go physically push a button to confirm it on the device, and have it send back to you a transaction.  It's basically the OP's idea, but much more paranoid.  I have all the equipment to do this - maybe I'll start soon.

[Richy_T]

The best way to start doing this without putting the cart before the horse would be to write the C code that will run on all this magical dream hardware.

If it were me, I wouldn't use C (though cryptography in ASM might be a challenge) but a cheap PIC microcontroller with embedded USB hardware can be had for cheap. I don't know if it has the power to handle the application but proof-of-concept could be put together pretty quickly and reasonably cheaply (Microchip will even send you the chips for free).