A distributed ledger is a 'database' without a central administrator or central storage. Instead, each copy of the database replicates and saves an identical copy of the data and updates itself independently. A distributed ledger must:
- Have a mechanism for pushing updates from one node to all nodes
- Have a mechanism for ensuring that the only remote updates it accepts are 'encrypted' or 'secured' somehow
- When there is a time delay between ledger updates, there must be a mechanism for determining a consensus 'correct' ledger status between ledgers
These mechanisms must be driven algorithmically, not by human subjective thinking.
The inspiration for this question is the book The House of Rothschild about he spread of the Rothschild banking empire in the first half of the 19th century. The five Rothschild brothers each opened a 'branch' of the family bank in London, Paris, Vienna, Naples, and Frankfurt.
However, in real life, political tensions quickly pulled the banks apart into separate entities. But, what if the family tried to keep the bank together. Perhaps with some algorithmic way to distribute and verify transactions, they could have maintained one banking entity up until the digital age?
How could a multi-national bank implement a distributed ledger to track its operations across an area the size of Western Europe?
The technology period for implementing this ledge could be anywhere from 1850-1950. For the sake of this question, ignore the political issues facing a multinational bank and focuses on the technology. Assume this takes place on an alternate-Earth where there are no World Wars or Protocols of the Elders of Zion.