The co-operative in March published the findings of a 12-week period of sandbox testing, in which almost 5,000 transactions were simulated between two different blockchain networks and with existing fiat-based payment systems. The beta solution has taken its next step, with three central banks and monetary authorities, including the Hong Kong Monetary Authority (HKMA) and the National Bank of Kazakhstan, integrating the solution with their own infrastructure for direct testing.Swift has also initiated a second phase of sandbox testing, in which commercial banks, central banks and financial market infrastructures are exploring additional use cases, including trigger-based payments for digital trade platforms, foreign exchange models, delivery vs payment and liquidity saving mechanisms. The Reserve Bank of Australia, Deutsche Bundesbank, HKMA, Bank of Thailand and CLS are among the enlarged group of more than 30 leading institutions in this second phase.Tom Zschach, chief innovation officer at Swift, says: “Our focus is on interoperability - ensuring that new digital currencies can seamlessly coexist with each other and with today’s fiat-based currencies and payment systems. The financial community has already recognised the strong potential of our CBDC innovations for preventing digital islands while securely bridging the payment systems of today and the future. This next phase of testing and exploration will help us further refine the solution to ensure it is as effective as possible, and at scale.”