Possibly useful libraries

camera-proj.txt

API levels:
  Nexus S:  10 (6%)
  Nexus 7:  17 (18%)
  ?         19 (39%)

Cameras:
  Open Camera
    http://opencamera.sourceforge.net/
    http://sourceforge.net/p/opencamera/code/ci/master/tree/
    
  A Better Camera
    http://abc.almalence.com/
    https://github.com/almalence/OpenCamera

Encryption:
  Bouncy Castle
  GPGPME (Guardian)
    https://guardianproject.info/code/gnupg/
  OpenSSL?
  APG
    http://www.thialfihar.org/projects/apg/
    https://github.com/thialfihar/apg
  OpenKeychain
    http://www.openkeychain.org/

JPEG/Exif/JFIF:
  
  
Notes (for simplicity in prototype):
  - Assume public key stored in SD card root
  - Add image to resources to use as default cover
  - Put all encrypted photos in special directory so user knows what they are
    - Give it innocuous name
  - Use only vertical orientation (could exclude tablets?)
    - Single fragment?

Activites:
  - MainActivity
    - Two buttons, one for selecting key from SD card
    - Second button to open PhotoActivity, only works if key available
    
  - PhotoActivity
    - Take simple photos, no options
    - Encrypt & save, using key & default fake photo