Blockchain, the computer network on which bitcoin sits, has caught the imagination of the financial services industry in the past six months for its potential to overhaul the sprawling and complicated network of bank payments and settlements. It is seen as a way of instantly updating payment ledgers in multiple locations without a single, centralized authority. Nine of the largest investment banks, including Goldman Sachs, JPMorgan and Credit Suisse, are planning to develop common standards for blockchain technology in an effort to broaden its use across financial services.