This seems like just the sort of thing big banking would've caught whiff to and become engaged in. Though I imagine it would remain under wraps...not the sort of thing well suited to be interfacing the general public. At least until perhaps some startups had gotten the ball rolling on this ball of wax. But for big multinational (secret) interactions? How better to enforce contracts? The advantages on that scale of avoiding legal entreaties and a digitized security system would be enticing.