Comment by kozikow | Hacker News Reader

Comment by kozikow | Hacker News Reader

Parent Full thread

I know that "why not blockchain" has become a cliche and I agree that majority of proposed use-cases seem like hammer desperately looking for the nail, but maybe this is an area where it could be indeed useful?

- Create a special "evidence camera" that allows photos taken with this camera to be used as an evidence.

- When you take the photo, the camera posts digital fingerprint of the photo on the blockchain.

- To prove that camera internals have not been tampered with, it also signs the fingerprint with the "camera private key". The private key is destroyed when the camera case is opened: for the sake of the argument let's say that the value of the air pressure inside the tightly locked camera case is the private key.

- The public key of the camera is publicly known, so everyone can verify the validity of the private key.

The challenge of your solution is that these situations are those that most deeply need anonymity.

You want proof of the veracity of the audio or visual evidence but the person(s) taking it and getting it out to public view desperately need to not be identified. Or at least they can't be connected to any network while collecting evidence (i.e. video of something unseemly happening in China/Somalia/DRC).

Deepfakes are a very hard problem and solely technical solutions are unlikely. A mix of context, reputation of the recording provider, and technical analysis is far more likely to be the right approach than any flavor of the month technology, be it block*, Erlang, Rust, or capsules.

At best, that that setup lets you prove that a certain pattern of light was present on the camera sensor at a certain time. It says nothing about the way the pattern was created, whether it was pointed at a real scene, or whether someone projected a faked movie into the camera.

By extension, any scheme to prove the truth of arbitrary measurements (audio, video, anything else) is vulnerable to manipulation of the measured value itself. The only way to be sure that something isn't fake is to experience it yourself (at least until virtual reality improves far enough to make even personal experience unreliable).

Worse still, this sort of simple manipulation of the analog data to the sensor would allow the camera to lend a sort of credence to faked images.

Reply on news.ycombinator.com