distributed database like BigTable 2 scales to large datasets and transaction volumes by spreading the data over many computers. However it is assumed that the computers in question are all run by a single homogenous organisation and that the nodes comprising the database all trust each other not to misbehave or leak data. In a decentralised database, such as the one underpinning Bitcoin 3 , the nodes make much weaker trust assumptions and actively cross-check each other’s work. Such databases trade performance and usability for security and global acceptance