[Thali-talk] QR codes

[Yaron Goland]

So I tried out the app and I have a few observations.

Repeat after me: Android Studio! :) Oh well, at least I now know the Eclipse importer really well on Intellij.

Unfortunately the camera didn't activate on my Samsung Galaxy S4 running 4.3. To be fair though I have had camera issues with the phone in the past. But usually a fresh reboot cleared up those problems and the phone was freshly booted and completely unused when I tried out your app. My N7 running 4.4.4 however worked just fine.

I also noticed that the QRCode you used was small. We got those working pretty well as well. But to move a decent sized key you will need a lot more data and that is where we ran into issues. It often worked but it was tricky. I suppose you could try a hybrid approach where you pass some kind of validation hash via QRCode and then the actual data via BLE/Bluetooth/Wi-Fi direct. But to make this "secure" against someone observing the QRCode you would need a hash long enough to make a rainbow table attack not work. Which I suspect would bring you back to the big QRCode issue.

I also think that having to stick the phones in front of each other is still tricky but I'm probably a Luddite.

    Thanks,

            Yaron

-----Original Message-----
From: Michael Rogers [mailto:michael at briarproject.org] 
Sent: Tuesday, March 31, 2015 4:36 PM
To: Yaron Goland; Nathan of Guardian; thali-talk at thaliproject.org
Subject: Re: [Thali-talk] QR codes

OK, proof-of-concept code is here:
https://code.briarproject.org/akwizgran/qr-code-test

I've only tried it on two phones so far, but it seems pretty usable. Let me know what you think.

Cheers,
Michael

P.S. Oh, my, God, the Android camera API is horrible.

On 27/03/15 18:24, Yaron Goland wrote:
> This is what Michael was saying he is going to try. I explained in my 
> response why I was dubious but this is one of those things that a 
> quick demo can settle. If you can get a super great reader that 'just 
> works' then maybe it would work? We didn't find such a reader but that 
> doesn't argue that it couldn't exist. If it does then we'll happily 
> use it too! :)
> 
> 		Yaron
> 
> -----Original Message-----
> From: Thali-talk [mailto:thali-talk-bounces at thaliproject.org] On 
> Behalf Of Nathan of Guardian
> Sent: Friday, March 27, 2015 11:08 AM
> To: thali-talk at thaliproject.org
> Subject: Re: [Thali-talk] QR codes
> 
> 
> On Fri, Mar 27, 2015, at 01:53 PM, Michael Rogers wrote:
>> 1. Users 1 and 2 put their phones into exchange identity mode
>>    - QR code on the top half of the screen, viewfinder on the bottom 
>> 2. Users 1 and 2 scan each other's codes, in whichever order they like
>>    - When a phone has scanned a code, the viewfinder becomes a tick
> 
> (Hi everyone!)
> 
> I have been thinking along these same lines... having a built-in customized viewer and display mechanism to make it more streamlined.
> Also, what about using front-facing cameras for this process, just to see if you could magically place two phones opposite side up from each-other and have it happen in one step?
> 
> +n
>