According to this (nice) video, mobile boarding passes are the future (18 airports in the US, by 5 airlines, also in EU by KLM/AF). In itself this seems to be a valid statement although the editor did not think the whole thing through..... The barcode may be encrypted, and even contain someone's name, but if that is not checked again at the gate, it would be very to use someone else's boarding card.

A boarding pass combined with some biometric id (checked once by a trained) professional will be common in the future. Using a the biometric information in the newer passports in the world new problems, as most encryption keys are managed at a national level.