ENHANCING SUPPLY CHAIN TRACEABILITY AND SECURITY THROUGH SMART CONTRACT INTEGRATION

Abstract

Modern supply chains span many organisations that do not fully trust one another and that keep records in separate systems. This makes it hard to trace a product from raw material to retail shelf, to prove that records have not been altered, and to settle payments promptly when goods arrive. Blockchain and smart contracts offer a shared, tamper-evident record and automatic enforcement of agreed rules, but a single blockchain rarely suits every participant: manufacturers often want a permissioned ledger that keeps commercial data private, while retailers and financial partners prefer a public platform with open settlement. This paper presents a cross-chain architecture that integrates smart contracts on a permissioned network used by suppliers with smart contracts on a public network used by retailers and finance partners. A logistics middleware bridges the two, supported by an oracle network, an authentication and access control layer, a zero-knowledge proof validator that lets regulators verify compliance without seeing confidential data, and a data integrity layer that records audit trails from both sides. Large documents are stored in a distributed file system, split into encrypted shares, and anchored on the chain. The architecture was implemented as a prototype and compared with a conventional cloud-based platform. Integrity verification time was on average 40% lower than in the cloud platform across file sizes from 50 to 350 kilobytes, falling from 8.1 to 4.3 seconds at the largest size. End-to-end traceability queries returned in under two seconds, and automated payment release shortened settlement from several days to a few minutes in the test scenarios. A threat analysis showed that the design resists tampering, unauthorised access, and replay attacks. The results suggest that integrated smart contracts can improve both traceability and security in multi-party supply chains.