Blockchain, or to use the wider term decentralised computing, could represent the next shift in computer systems thinking, following on from the likes of the internet, client-server architectures and databases. However, it faces a real risk that initial attempts at deploying blockchain don't deliver the expected benefits, expectations are not met, and as a consequence its wider adoption is set back. Typical expectations are that transactions will be faster, transaction costs will be lowered, and that the system will have integrity and so be trustworthy. Integrity and trust is a major point, particularly when people have lost faith in existing [...]