Privacy based smart contract modeling using the UTXO model with DAML

Blockchain is an area of opportunity for multiple fields, not only does it work for financial applications such as bitcoin or Etherium, but it also has opportunity for other type of applications. Business process management systems are commonly used for the creation, monitoring and optimization of business processes, and while there exist several BPMS there is no currently used one in the Blockchain. The main reason why companies are not using Blockchain hosted BPMS is due to the confidentiality problem native to the very same Blockchain, since all transactions are public in the Blockchain; due to security concerns, there is no native implementation for confidentiality in processes. That is why for a BPMS to be used in the Blockchain it has to be created with confidentiality in mind. In this thesis I wish to present a possible solution to the lack of confidentiality in the Blockchain, and inspire further work to implement a whole BPMS using DAML smart contract language as a solution. However in contrast to past work that has used a native BPMS to create business process models and translate them into smart contracts, DAML runs into an impedance mismatch with the used BPMS, BPMN. DAML being an UTXO smart contract language places a lot of emphasis on information flow, which is contrary to the action oriented BPMN. Due to this, it was decided that a new modeling language based on the JOpera ideas of what a visual language has to be was going to be created which was aptly named Graphical DAML. With the creation of this Visual language based on UML, the translation processes between GDAML and DAML had to be done, in the end a middle step between these two was added in the form of a JSON object. With the translation process complete, testing on DAML as a solution proved to be successful as the processes kept privacy and confidentiality of the users, the contracts and the information therein hidden to every user that was not pertinent. After all this, future work is recommended to extend this application and all resources are shared with the readers.

https://orcid.org/0000-0001-9076-903X