Anupa Shyamlal, John Breslin, Subhasis Thakur;  University of Galway

The advent of blockchain as a technology is revolutionising the supply chain domain with its tamper-proof and traceable architecture. However, the blockchain must be fed with accurate data, especially in supply chains where data origin is outside the blockchain.

A supply chain is a collective operation among multiple stakeholders that encompasses the process of raw materials to become the end product and reach the consumer. The events triggered by the entities and data emanating from sources such as Internet of Things devices during the process are complex and scattered. These IoT data might include manufacturing data, card payment data, shipping and transport data, customs data etc.

Therefore, a transparent and tamper-proof platform like blockchain is nifty to securely share the relevant knowledge among the involved parties and trace it back in case of an issue. Blockchain is a system in which a record of transactions, especially those made in a cryptocurrency, is maintained across computers that are linked in a peer-to-peer network and can be traced from beginning to end.

However, the provenance of the supply chain data must be trustworthy for all the stakeholders because, unlike cryptocurrency-based blockchains, the origin is not verifiable within the blockchain itself when it comes to the supply chain.

For example, in a food supply chain, the consumer cannot be convinced of the quality of food using the inputs from the IoT devices managed by the same farmer who produces the food.

Such external inputs to the blockchain are known as data oracles. An oracle sends data from the outside world, e.g temperature, to a blockchain.

This project proposes an end-to-end decentralised payment protocol for the supply chain domain, assuming a trusted data oracle system feeding data to the system. The protocol facilitates remunerating all entities between the consumer’s transaction initiation and when the product is received.

The independence of data oracles is crucial, and it allows supply chain stakeholders to focus on their work as well. Using the payment channel network (PCN) concept, we propose a low-cost payment protocol for supply chains with an independent and trusted data oracle environment. It ensures the atomicity of the end-to-end payment from a consumer to the manufacturer, including other participants and data oracles.

Further, if the primary transaction fails, the oracle environment is still compensated regardless, and the consumer is not held liable for that payment. We present how to achieve this unique type of atomicity requirement and discuss its potential, security and future direction.