Description
Orchestrating and tracking the steps and cross-party messages of business collaborations is a key blockchain/distributed ledger technology use case. Several tools have emerged to support blockchain-orchestrated BPM (business process management); an important subset of these takes models of the cooperation, usually captured in the Business Process and Notation (BPMN) language and generate a process manager smart contract from the model.
Most of the existing tools target Solidity, and all of them store the business process state in the clear, in the smart contract. This can be problematic even for Hyperledger Fabric – if the process state is not to be seen by the whole consortium, we must resort to the confidentiality toolbox of Fabric (multiple channels, private data collections, etc.).
We argue that this is not absolutely necessary; in a recent work (published as open-source at: https://github.com/ftsrg/zkWF) we created a hash-commitment scheme-based business process orchestration approach, relying on zk-SNARKs for proving the admissibility of process state commitment updates.
Our prototype implementation already supports Hyperledger Fabric to some extent (originally, we focused primarily on Solidity/EVM). Specifically, we have an implementation of the crucial element, the commitment-manager and proof checker chaincode. However, proper support for Fabric needs a number of further improvements – as contributions to our open-source solution - and this is the topic of this mentorship.