Yeah, with J3M, it relies on the user to supply their own sensor data,
   which is obviously problematic if the use case is to prevent forgery
   (if it's just for archival purposes, it works fine.) With a networked
   system, the location would be determined from the traffic source or
   similar.
   On Mon, Aug 26, 2013 at 5:25 PM, Lee Azzarello
   <[1]lee@guardianproject.info> wrote:

     I don't fully understand the model that excludes GPS data as a
     provider of a "specific place". Would the GPS satellites and ground
     units be an "external" data source? If so, is your assertion that
     GPS
     data from a device's logging app could be forged in transit?
     -lee

   On Mon, Aug 26, 2013 at 8:12 PM, Rich Jones <[2]rich@openwatch.net>
   wrote:
   > I'm familiar with J3M, but unfortunately none of the current
   J3M/informacam
   > techniques actually work, as they have no _external_ verifiability.
   There
   > isn't actually any information which ties the media to a place or a
   time,
   > it's just information encoded into data which could be applied to any
   > document at any time. By factoring the network, a geotemporal pkey
   system
   > would address this problem. J3M is good for tying information to a
   specific
   > device (sort of) - but not to a place or a time.
   >
   > R
   >
   >
   > On Mon, Aug 26, 2013 at 4:58 PM, Lee Azzarello
   <[3]lee@guardianproject.info>
   > wrote:
   >>
   >> Informacam
   >>
   >> "InformaCam is a mobile application for Android that enables users
   to
   >> inflate image and video with extra points of data, or metadata. The
   >> metadata includes information like the users current GPS
   coordinates,
   >> altitude, compass bearing, light meter readings, the signatures of
   >> neighboring devices, cell towers, and wifi networks; and serves to
   >> shed light on the exact circumstances and contexts under which the
   >> digital image was taken. With InformaCam the app starts to behave
   >> almost like Adobe Photoshop or GIMP, supporting non-destructive,
   >> layer-based edits to media built on top of Obscuracam."
   >>
   >> [4]https://guardianproject.info/apps/informacam/
   >>
   >> There is a sub-project to standardize metadata called j3m.
   >> [5]http://j3m.info/
   >>
   >> -lee
   >>
   >> On Mon, Aug 26, 2013 at 7:08 PM, Rich Jones <[6]rich@openwatch.net>
   wrote:
   >> > This is a small, unfinished idea I had, but I'd be interested in
   hearing
   >> > any
   >> > feedback anybody here might have to offer. Normally we talk about
   >> > cryptography to secure communications, but this is an idea rather
   about
   >> > verifying the authenticity of media.
   >> >
   >> > [Quick backround: OpenWatch is a global citizen media network
   using
   >> > mobile
   >> > phones as the basis for a free worldwide press. We care very much
   about
   >> > the
   >> > authenticity of citizen media, and have designed some systems
   which
   >> > attempt
   >> > to improve the verifiability of citizen media.]
   >> >
   >> > The problem is that sometimes media artifacts are presented as a
   record
   >> > of a
   >> > current event, when in fact they from different events. An example
   of
   >> > this
   >> > was when images of a marathon race in Istanbul were presented as
   images
   >> > of
   >> > the recent Occupy Gezi protests.
   >> >
   >> > Now, imagine the globe divided into a grid coordinate system, say
   >> > 100,000
   >> > units (or perhaps 232, if IP rather than physical address is to be
   >> > used).
   >> > Based on their physical location, reporters can contact a server
   and are
   >> > assigned a key with which to sign or encrypt their media to. This
   then
   >> > ties
   >> > a media object to a physical space. This can be further improved
   to
   >> > include
   >> > both time and space by dividing a space-day into a number of
   units,
   >> > suppose
   >> > 1440, such that different keys would be handed out at different
   times of
   >> > the
   >> > day, thus further tying a document to a moment in time as well.
   >> >
   >> > Does anybody know if any systems like this have ever been
   discussed or
   >> > designed in the past? I suppose this is somewhat similar to the
   >> > RSA-keyfob
   >> > system, although this allows for anonymous access without
   >> > pre-arrangement as
   >> > well.
   >> >
   >> > R
   >>
   >
   >
   >
   > --
   >
   >
   > Rich Jones
   >
   > OpenWatch is a global investigative network using mobile technology
   to build
   > a more transparent world. Download OpenWatch for iOS and for Android!

   --
   Rich Jones
   OpenWatch is a global investigative network using mobile technology to
   build a more transparent world. Download OpenWatch [7]for iOS and
   [8]for Android!

References

   1. mailto:lee@guardianproject.info
   2. mailto:rich@openwatch.net
   3. mailto:lee@guardianproject.info
   4. https://guardianproject.info/apps/informacam/
   5. http://j3m.info/
   6. mailto:rich@openwatch.net
   7. https://itunes.apple.com/us/app/openwatch-social-muckraking/id642680756?ls=1&mt=8
   8. https://play.google.com/store/apps/details?id=org.ale.openwatch&hl=en