Trusted notary networks and swift

Work  fine together.  So, a group of big backs can create the clearing net, covering 75% of the market with their own transactions. They use Telegram, which is a framework, really. And swift is is simply using a distributed spanning tree instead of the correspondent bank hierarchy. If SWIFT is well written.

So, some group of fiat banks convince the Fed to allow this, they all go into the business of policing bearer digital tax dollars for their client. 

Account verification

Any of the trusted notaries is operated by a bank with some, possibly overlapping, number of accounts, or clients.  Any transfer, we assume is from one account in one bank to another.  Any of the notaries then on seeing the  transaction request my accept, because it had not recently seen a conflict; the net has bound time of traversal, and a timeout itself.

So most of the bank are neutral, see no conflict. The one bank with the source account can issue a confirm, and mark the books.  Even after a confirm issued the remainder network may observe a conflict and issue a reject, which over rides.

Transactions can overlap, but there is a residual rejection timeout that must be honored  That time is mostly log of total number  of notaries,which is small.  The timeout comes quickly.  The timeout operates this way because reject overrides confirm, making the system is much safer. If confirm over rode than clearance is typically N , the number steps needed to reach the confirming bank and back, then the system picks one or the other of double spends and we rather catch the scofflaws by rejecting in total.

Why would banks do this?

They get instant infrastructure  for optimum tax dollar accounts and receive monopoly fees. They are instantly supported by Telegram bots. They see an order of magnitude increase in volume-variety.  Sequential protocols powerful.

Increased reach

On the liquidity net, the bank collective can offer lending and deposit, bear the currency risk,  get more customers, make more fee.

The retailers and delivery services already connected to swap net, they keep a merchant account, their own bank  Stock market pits open and connected. From the client trading bot, it appeeas like a huge OTC maret, everything.