Abstract: A block chain data lake system comprises a data lake of a plurality of data files and software applications interfacing the data files. The system further comprises a block chain and block chain controller therefor. A transaction controller monitors transactions performed on the data files by functions of the software applications to add hashes to blocks of the block chain using the data files. A verification controller may verify data files by searching the block chain for hashes matching the data files. An authentication controller may issue cryptographic keys for software application, including specific functions thereof. A data migration system may migrate data from a legacy data system to the block chain data lake system. A synchronisation controller may synchronise data updated by software applications of the legacy data system in substantial real-time.

Abstract: A block chain-based system for multi-party, multistage process verification has a server in operable communication with a plurality of electronic client terminals. The server has a database which may have user data and implement a process verification controller. The system further has a block chain ledger. Fora multistage process involving multiple users, for each stage, the system is configured for receiving a function ID selected from a set of available functions via user interfaces of respective client terminals, generating a function hash comprising the function ID and associated function data and creating a function block chain transaction comprising the function hash which is added to the block chain ledger.