Feature Request: Possiblity to securely transfer unsigned transactions between online and offline wallet

[b52-]

Since more and more usb-key viruses appear, it would be great to securely transfer transactions between online and offline wallets. Since these transactions don't consist of much data it could be possible to transfer them as QR-Code. This is almost implemented.

• The online client would create a QR of the unsinged transaction.
• The QR-Code could be read with a cam on the offline computer. The QR could be either read by an external program and saved as file which is then opened by the offline client, or it could be read directly into the offline client if armory would support that cam.
• We can use the same method to get that signed transaction back into the online client.

This way direct data exchange between these computers is not needed and thus more secure.

So long, b52

[etotheipi]

This has been discussed in the Improving offline wallets thread. It's a good idea, but it's only a 90% idea -- there's quite a few use cases where the transaction data to be transferred would require dozens of QR codes... it would be kind of messy, and the user would be juggling multiple webcams and wires and trying to figure out which ones to point where...

That's not to say it won't work. But since it's not going to work for all transactions, I wanted to focus on something that will. Serial will definitely work, if I figure out how to check that the serial connection is actually secure. I also put out a bounty for audio channel transfer due to the fact that it would have a very high level of security, and would work with smartphones, too (which don't have serial ports).

At some point, I'll get around to implementing something more secure, but for now the offline USB key transfer is an order of magnitude safer than keeping an encrypted wallet online, so I'm focusing on Armory usability first.