[ardy42]

> I wonder what encryption and key based techniques can be used to verify the authenticity of audio and video records in the future.

None, since encryption isn't the answer to this problem. Take Romney's leaked "47%" comment [1] or Hillary Clinton's leaked "deplorables" comment, how would encryption have been useful to either verify the recordings' authenticity or reject them if they had been a deepfakes? It wouldn't have, as those comments were meant for private audiences, so neither of them would have officially signed them. If the encryption could trace the recording back to the individual that made it, then the leaker might decide never release the recording (since they don't want to be outed). And if all the encryption can do is trace back to a random device, why not just get a random device to sign your deepfake?

[1] https://www.npr.org/sections/itsallpolitics/2012/09/17/16131...

[2] https://www.npr.org/2016/09/10/493427601/hillary-clintons-ba...