document "split-bitcoin" (watching / cold wallet) implementation

[mfc]

it is a lot simpler than this qubes-users thread:

https://groups.google.com/d/msg/qubes-users/AkZo8xOxi18/-pgvSV6FDwAJ

first section of page would introduce the concept, maybe highlight which clients have the cold wallet / watching wallet capability. second section would go through how one would set it up with one example client. I set it up with electrum and it was quite easy, just had to install jessie-backports.

very low priority but something that is likely of interest to Qubes users (or potential users). There may already be documentation out there on it, just not in the google group.

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How to set up offline "cold storage" bitcoin wallet and an online watching-only bitcoin wallet:

1. Create a Debian 8 backports template using the Qubes VM Manager or running
   qvm-clone debian-8 debian-8-backports in dom0.

2. Add backports to the sources for the new template by opening a terminal in
   the new template, run sudo vi /etc/apt/sources.list and add
   deb http://http.debian.net/debian jessie-backports main.

   (If you are new to vi text editing, type i to be able to edit, and when
   done editing press ESC then type :x and press ENTER.)

3. Update source list: sudo apt-get update.

4. Install electrum from backports:
   sudo apt-get -t jessie-backports install electrum.

5. shut down your debian-8-backports template

6. create an offline-bitcoin qube based on debian-8-backports using the Qubes VM Manager or running qvm-create -t debian-8-backports -l black offline-bitcoin and qvm-prefs -s offline-bitcoin netvm none in dom0.

7. follow the electrum documentation in creating an offline wallet

8. create a watching-bitcoin qubes based on debian-8-backports connecting to the internet how ever you prefer using the Qubes VM Manager or running for example qvm-create -t debian-8-backports -l green watching-bitcoin and qvm-prefs -s watching-bitcoin netvm sys-whonix in dom0.

9. follow the electrum documentation in creating an online watching-only wallet

[bnvk]

This is really nifty, perhaps we should add Bticoin or cryptocurrency enthusiast as a persona type in #1906

[mfc]

@andrewdavidwong when you have the chance could you super-briefly frame this guide like you did for Martus and put it up (I guess in the privacy section)? you did a great job with that one.

[andrewdavidwong]

Sure thing. It's available here. (I decided to put it in /security because I think it'll be a slightly better fit for that section.)

[mfc]

added content to that, would be great to push it up if it looks good.

[andrewdavidwong]

@mfc: Looks good; merged. :)

Does anything else need to be done for this issue?

[mfc]

all good :)

[adrelanos]

This still needs to be added to documentation index https://www.qubes-os.org/doc/?

[andrewdavidwong]

Ah, of course. Added. Thanks, Patrick.

[TomzBench]

electrum 2.7.9 has a offline transaction signing bug and the qubes documented repository only has this version. Is there a recommended way to update the template electrum to 2.7.11 with bug fix?

Some references to mention of bug links:

spesmilo/electrum#2146

https://labs.riseup.net/code/issues/12323

[marmarek]

Any more information on this bug? I do use the above setup without any problem...
Anyway, you can use Fedora template - Fedora 25 have electrum 2.8.3.

[TomzBench]

It is bug in electrum only specific to version 2.7.9. When signing transactions the offline mode electrum still will try to connect to network and you get timeout error. Downgrading would fix problem also.

I used the template documented in qubes-os docs. So I think the qubes docs should change the template in the instructions, or upgrade or downgrade electrum package in the template.