Quote from: kkurtmann on February 27, 2015, 08:09:10 PM

Quote from: dsattler on February 27, 2015, 07:46:36 AM

Quote from: rekoa12 on February 25, 2015, 09:45:13 PM

There is a new wallet concept - http://www.eliptibox.com/. First to talk about firewall on hardware and packed with features.
Can be interesting platform for developers.

Interesting concept, thanks for sharing. What does "fpga hardware firewall" means? Why do you need this if you do only offline signing? I don't assume that this wallet downloads the blockchain to let you view your transactions.

I also was wondering why a field programable gate array would be used as a firewall. Apparently it does download block headers and stores tx info on the device, so says their site.

FPGA enables complete decoupling between the communication messages wallet-external app and the wallet crypto code.

With regular microcontoller (that all HW wallets use) the code you write in editor is not the code that runs on the device. Compiler optimizes (=rewrites) it and linker adds large blocks of 3rd party code automatically. Furthermore, usually the messages data is at the same physical memory as the code, so it is possible to change the code of the microcontroller by malicious message injection that exploits bugs in the chip design or the code. (buffer overflow as a common example).

If the same microcontroller is connected directly to the external interface, like USB, Cellular or BT, remote attacker can gain control over the interface and base his attacks from inside the wallet. We often read about new interface breach, like in USB or GSM or weak BT.

However, in FPGA you run exactly the code you've written and can verify it by looking at the final silicon configuration. There is no software or ability to change the FPGA code when running. So the code for the internal MCU can be upgraded and multiple external non-secure interfaces can be used without breaching the security.
FPGA chip sits in-between and makes sure only "legal" data goes through.

www.eliptibox.com