The problem of enforceability If legally binding, the technology (especially in permissionless systems) may raise enforceability issues Reasons for this: No central Evidence administering authority and proof  Absence of administrator in permissionless  No obvious defendant (e.g. defective systems program logic or data corruption)  Lack of administrator decision could force  Pseudonymous nature of some transactions parties to court  Proof of existence or content of entirely electronic smart contract  Problems enforcing court judgment or arbitration award in relation to blockchain UNRESTRICTED 160