How will decentralised bitcoin technology help nine of the world's largest banks, including Australia's CBA, Barclays and JP Morgan, become more efficient? The Commonwealth Bank of Australia will work with some of the world's biggest banks to turn the technology behind digital currencies often used by criminals and computer hackers into a safe way to transfer money around the world and potentially replace the cumbersome international money transfer system. The banks plan to design "distributed ledger" technology based on the "blockchain" that facilitates bitcoin transactions.