I doubt their private blockchain will work for the very same reason they want a private blockchain - they&#x27;re not trustworthy. The bitcoin blockchain is secured by the large number of disparate people mututally checking the system. When it&#x27;s just banks involved the number of players is reduced by many orders of magnitude and it becomes very much easier to game the system.<p>The incentive to steal large amounts of money is high and the security is relatively low. What could possibly go wrong?