American Express has filed a patent for a blockchain-powered proof-of-payment system
from Cointelegraph.com News https://ift.tt/2L6GGAR American Express Files Patent for Blockchain-Powered Proof-of-Payment System
American Express has filed a patent for a blockchain-powered proof-of-payment system
from Cointelegraph.com News https://ift.tt/2L6GGAR American Express Files Patent for Blockchain-Powered Proof-of-Payment System