Booths

A Progressive Web App for paperless booth visit provisioning. Deployed to https://earthday.firebaseapp.com

Usage

Define booth list on the firebase backend, and also provide the same data in the off-line default store (jsonp file)
Generate RSA public/private keypair at http://www-cs-students.stanford.edu/~tjw/jsbn/rsa2.html
RSA library is extended with sign/decodeSign capability to accomodate our use-case
Encode booth key for each booth and generate QR codes for them
Distribute the QR codes (generated by http://goqr.me/, listed on https://github.com/bulldogearthday/boothQRs
Make sure the visitors only see the booth's QR code when they completed the booth's quest
The visitor can then scan the QR code, unlocking the achievement

Progressive Web Apps provide a way to have mobile app on multiple platforms without going through the hoops of releasing separate native apps into native app stores
Progressive Web Apps work best with Chrome browser but with polyfill libraries other browsers could still provide the required features
The user can take a picture of the specific QR code of a booth. The QR code will cryptographically prove that the individual visited the booth
Using getUserMedia for visual capture (see e.g. https://github.com/samdutton/simpl/tree/gh-pages/getusermedia)
Using MediaStreamTrack for video source selection (https://github.com/samdutton/simpl/tree/gh-pages/getusermedia/sources)
~~Using jsQR for QR scanning (https://github.com/cozmo/jsQR)~~
Using Lazar Laszlo's https://github.com/LazarSoft/jsqrcode
Using http://www-cs-students.stanford.edu/~tjw/jsbn/ for RSA encryption/decription
The App should be able to operate off-line from cached data
Firebase backend provides booth data
The data is basically the list and properties of the booths

~~Fallback for browser which doesn't support getUserMedia~~
Computation server side for better security
Minimize JS and even code to make cheating harder
Minimize all assets (smaller icon data, minimize CSS too) for decrease load time and better bandwidth
Inline everything together for faster experience
~~QR code would read automatically and no SCAN button needed~~
Improve cross-platform and cross-browser coverage - improved, but there's always more space for improvement