That you _can_ solve it with a blockchain doesn't mean that you can _only_ solve it with a blockchain.
M valid signatures of N authorities is a consensus mechanism that just needs public keys. You don't need a blockchain if you're prepared to trust a set of authorities like stripe and their trusted partners.
M valid signatures of N authorities is a consensus mechanism that just needs public keys. You don't need a blockchain if you're prepared to trust a set of authorities like stripe and their trusted partners.