Here’s how I timestamp photos manually:

I print out a news article and place it in every photo so that the headline shows. Today it could be this headline from CNN: “Freddie Gray death: New narratives question police brutality claim”. This proves that the photos were shot after this article was published.

I organize all photos in a zip file, then broadcast the file’s hash with Counterwallet. This proves the photos were shot before the broadcast.

I wonder if there is a more convenient, automated way of doing this?

A camera app could broadcast the hashes automatically. The camera would send the hash of every photo to a centralized server. All hashes from all users of this app would be collected in a single file, and the hash of this file would be broadcast on the Bitcoin blockchain. This could be repeated frequently, say every ten minutes. Now this would prove that photos existed before the broadcast. Such an app wouldn’t be too difficult to make, would it?

The part of embedding current data in the photo (equivalent to the newspaper headline) would be harder, wouldn’t it? Of course, some current data could be stamped on each photo, but how to prove it is not just stamped onto some old photo? When I include the printed paper in my photos, on the other hand, the proof is stronger because it is difficult to photoshop a paper into a photo (or is it? I know little about this).

A workaround, although not perfect, is that all photos from the same app, include hashes of previous photos. Any better way of doing it? Has someone all ready made such an app? Does Factom plan to make one?