Today, more and more transactions are being handled online across a broad range of categories. Transactions can be Business-to-Consumer (B2C) and Business-to-Business (B2B), local and international, goods and services, and can be settled using credit cards, bank transfers or peer to peer payment networks. While different approaches have been deployed to ensure the safety of data transmission and to verify the identity of the parties, very little has been done to ensure that the transactions are memorialised in a secure and reliable manner.