Digital twins and dynamic NFTs for blockchain-based crowdsourced last-mile delivery

In this paper, we propose a blockchain-based crowdsourcing framework leveraging Digital Twins (DTs) and dynamic Non-Fungible Tokens (NFTs) for a transparent last-mile delivery. Existing works propose package delivery through crowdsourced workers managed by centralized or blockchain-based platforms. While the centralized platforms suffer from data security and reliability vulnerabilities, the blockchain-based platforms lack real-time and transparent package status monitoring. The availability of immediate access to status updates and early warnings regarding package storage conditions greatly contributes to ensuring the safe delivery of sensitive packages and preventing spoilage or further damage. As a solution, we propose a decentralized crowdsourcing platform for last-mile delivery utilizing Ethereum smart contracts and DTs for both the packages and the workers. The contracts are leveraged to facilitate interactions between the requesters and workers, and securely execute the task allocation mechanism, which relies on a computed Quality-of-Service (QoS) metric. The package DTs are proposed to oversee the package status and promptly alert workers’ DTs when delivery conditions are violated. To ensure data integrity and prevent malicious alterations, the DTs’ data is securely stored using NFTs. Upon task completion, a calculated Quality-of-Delivery (QoD) acts as a feedback loop in updating workers’ reputations. The proposed allocation mechanism is benchmarked against distance-based and preferences-based allocation mechanisms where our framework improves the average QoS by 76%, average QoD by 22%, and quality of selected workers by 11%. In addition, the DTs are implemented to verify alert generation through a use case. We provide a detailed cost analysis of deployed smart contracts, along with insights into current limitations and proposed mitigation strategies.