Investigate informacam

[patcon]

Meant for activists and protesters, but might cut out a few steps here while taking the passport photo:

https://guardianproject.info/informa/

[patcon]

Two related issues about getting informacam hashes into blockchain:

guardianproject/ChatSecureAndroid#510
https://dev.guardianproject.info/issues/1648

[MrChrisJ]

Amazing! Similar ideas have been coming to me too about media authenticity. This one idea, the Blockchain Camera, kept torturing my mind and we spoke about it at length at WCN: http://www.reddit.com/r/worldcryptonetwork/comments/2i2jlr/chris_ellis_proof_of_honesty_the_jesus_attack_the/

It employs the same technique of embedding the Merkle Root of the latest block as well as forming its own internal merkle tree between frames to authenticate the content. Then finally to prove that it is not just footage of another screen we employ a challenge response to prove the operator is conscious and to break the fourth wall. To do this simply take the current merkle root, concatenate it with the hash of the first 30 frames and from there issue a set of instructions like pointing the camera up, down left right etc.

Now this can be done at any stage during the video but once the recording is stopped it's important distribute the merkle root of the whole content as quickly as possible to minimise the window of opportunity for corruption.

In the past timestamping was limited to proving content existed at Time 1 and any time prior. With this technique we lock down a sequence of events to a window of time thus removing the incentive to lie at all. Essentially you are removing the gaps from the world.

Thanks so much for the pointer.