> We need a way to do digital signatures on images such that they cannot be faked.
This is almost impossible – the camera's processor can be tampered with and the environment can be altered (e.g. GPS spoofing).
The best we could do would be a notary service where a trusted third-party could produce a signature for a set of bits at a particular time. That would prevent either altering an unwilling third-party's photos or back-dating images after an important event.
All these are unreliable to an extent which suggests there will probably be a fair market for forensic photography software in the future…
This is almost impossible – the camera's processor can be tampered with and the environment can be altered (e.g. GPS spoofing).
The best we could do would be a notary service where a trusted third-party could produce a signature for a set of bits at a particular time. That would prevent either altering an unwilling third-party's photos or back-dating images after an important event.
All these are unreliable to an extent which suggests there will probably be a fair market for forensic photography software in the future…