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Interacting Decentralized Transactional and Ledger Architecture for Mutual Credit

Periodic Reporting for period 1 - INTERLACE (Interacting Decentralized Transactional and Ledger Architecture for Mutual Credit)

Reporting period: 2017-05-01 to 2018-10-31

The problem addressed by INTERLACE was the development of a blockchain-based transactional platform for the Sardex electronic business-to-business (B2B) mutual credit system by leveraging one of the outputs of the BIOMICS FET Proactive project, the Abstract State Interaction Machines (ASIMs). This is a technical innovation in bringing the blockchain to mutual credit, and also a methodological innovation in the use of the ASIM specification and modelling language for distributed, asynchronous, communicating systems. These two innovations strengthened the financial innovation of the Sardex mutual credit system itself, which was already 8 years old and supporting 3000 small and medium-sized enterprises (SMEs) at the beginning of the project. The blockchain architecture that INTERLACE developed to the level of a working prototype is important for the future scalability of the Sardex system as it is gradually extended to other Italian regions, European countries, and beyond, both for the platform functionality as well as the governance of the community.

The importance for society derives mainly from the Sardex financial innovation that INTERLACE has strengthened on a technical and methodological level. In fact, the Sardex system is now helping 4000 SME users and a similar number of their employees trade on the island of Sardinia. A similar number of SME users is distributed in 11 other circuits affiliated with Sardex in other Italian regions, and a business-to-consumer (B2C) product has just been launched.

INTERLACE elected to adopt the Hyperledger Fabric permissioned blockchain as one of the most well-established blockchain frameworks for the enterprise. Since Hyperledger also has an interface to Ethereum, over the coming years this will make it possible to develop, if needed or desirable, some of the Sardex services on a public and permissionless blockchain.

As a FET Open Launchpad project, INTERLACE had a very small budget. Therefore, the majority of the resources had to come from own funds/effort of the partners and/or venture capital (VC). However, VC funding did not materialise during the time of the project. Therefore, the level of achievement that could be reached was less than originally envisaged, in spite of the fact that the amount of work – including self-funded effort – was quite high. In spite of this set-back, the INTERLACE project was able to achieve most of its objectives:

1. Implement a blockchain-based transactional platform demonstrator to be tested with a subset of the current circuit member companies. Partially achieved: the transactional platform was achieved, but the testing framework and the field testing were not.
2. Extend the collaborative team of computer scientists that developed the ASIMs. Achieved.
3. Bring Sardex’s architecture to the current state of the art. Achieved.
4. Adopt a scalable and robust blockchain technology. Achieved.

In conclusion, the project was successful in starting Sardex in the direction of blockchain technologies and in strengthening its software engineering methodology. Over the next 2 years this work will be tested and gradually integrated into the new microservice architecture of the Sardex platform.
The coordination of the project involved 9 group meetings and many online meetings. The flow of information was large and of good quality, in particular through very detailed group e-mail discussions. In addition, we made extensive use of Github as a collaborative platform. Dissemination consisted in adopting open source for all the implementations, in the development of the project’s website, and in frequent references to this website at public events (5 events).

The architecture workpackage focused on the requirements and specification of the platform. A constant scouting and analysis of the suitability of emerging blockchain technologies for the future vision of the Sardex business and governance models led to the analysis of dozens of possible blockchain frameworks, of which six were studied in depth and one eventually was adopted. A lot of effort was put into the formalisation of the ASIM specification of a simplified set of business processes based on the current Sardex system. In the analysis of the emerging blockchain technologies, the challenge was to achieve scalability of the platform while retaining the fundamental principles of support for the local economy (in each region where a circuit is established), keeping a balance between social and economic values while supporting SMEs. The INTERLACE platform will serve as one of the services in the new Sardex microservice architecture, currently under development as the platform transitions from the previous relational database monolithic design.

The implementation workpackage implemented the ASIM specification in the CoreASIM language as a CoreASIM executable model downloadable from Github. Second, it implemented the Hyperledger Fabric blockchain consistently with the same specification. In order to achieve executable instances of the ASIM model and of the transactional platform a lot of additional preparatory work had to be done. For example, we spent a significant amount of time and effort setting up an appropriate execution environment that could run on any platform. In particular both Vagrant and Docker container environments were set up and tested on Linux, Windows, and Mac. A full-stack implementation of a B2B payment network was iteratively evolved into a DLT realization based on the CoreASIM ground model. Thus, this network implementation presents an implementation which acts as a template for a future production solution. To enable simple access to the payment infrastructure, a web front-end facilitating the REST-based microservices provided by the DLT was created. All of the projects are available on the INTERLACE Github repository (

The testing workpackage unfortunately was not completed. Although basic testing was performed to verify that the CoreASIM model and the blockchain implementation were both performing as required, we ran out of time and could not develop production-level testing frameworks for testing the components of the system against the requirements. As a consequence, we did not have time to perform field tests with a set of current Sardex users as had been planned originally.
INTERLACE’s contribution beyond the state of the art is to have developed a blockchain implementation for mutual credit. The socio-economic impact is expected to be very large. Sardex makes it possible for SMEs to grant each other working capital at zero interest in the form of mutual credit for the exchange of products and services. Given that 99% of all firms worldwide are SMEs, and given that SMEs’ working capital needs are chronically underserved by the banking sector due to the unfavourable risk weightings dictated by the Basel accords, the relevance and potential impact are huge. As the system grows in size, it will be important to be able to rely on an extensible, distributed platform such as a blockchain can provide and on a strong software engineering methodology for the development and maintenance of the platform. INTERLACE has enabled Sardex to take the first steps in this exciting new direction.