unique identifier, and thus all asset transactions could be confirmed and tracked via the blockchain.

As noted in [@barber2012bitter], the notion of scripting offered by crypto-currencies like Bitcoin is a highly useful and very innovative feature. It allows users to embed scripts in their Bitcoin transactions, this key feature is only just being recognised as a utility in its own right. It has been realized that at least in theory, as noted in [@barber2012bitter] that this can lead to “... rich transactional semantics and contracts through scripts, such as deposits, escrow and dispute mediation, assurance contracts, including the use of external states, and so on.”

The Bitcoin use-case is one where the blockchain used is permissionless. ‘Permission’ refers to the verifiers on the network, and in the case of Bitcoin, miners do not have to be authorised by a central authority before performing their mining activities. This is not the only model for a blockchain, however, and indeed the actors on the network who verify transactions can be subject to authorisation, as well as legal accountability. The applications outlined in this section span both modes of blockchain operation.

In its report, the EBA [^15] presents an analysis of cryptotechnologies in 