Banks and Blockchain?

In a patent application released by the U.S. Patent and Trademark Office last week, American Express Travel Related Services describes using a "blockchain-based system" in order to receive "payment confirmation including a transaction amount and a merchant identifier." The concept is aimed at adding to what AmEx calls the "limited" number of options for generating quality evidence that payments happen between merchants and their customers "beyond a receipt or ticket.

AmEx's patent highlights the tech's role in retaining "transaction data, contract data, proof-of-payment data, identification data, and/or other information as desired," with the idea being that a blockchain network possibly a public one would serve as an extra layer of proof for transactions that take place on AmEx's network.

What do you guys think? Banks and blockchain ?