Cryptographically signed streaming video recognition

I just had this idea about doing away with passwords. I was talking to a Toshiba Fellow Alumni who was describing how retinal scans etc. don't work well for remote security, so he was suggesting an n of m of personal possessions with RFID tags. However I was just thinking of combining face recognition of a live video stream, while having each frame of the video signed cryptographically with the current date using a private key belonging to the consumer ... would that give some degree of remote security ...?