Blockchain-Enabled IoT Tracking for a Real-Time, Tamper-Proof Cold-Chain Monitoring System in India’s Vaccine Supply Network

Abstract

India's vaccine distribution network is one of the largest and most complex in the world, serving over 1.4 billion people through its Universal Immunisation Programme (UIP).However, this vast network relies on a fragile cold-chain that is often monitored through manual, paper-based logs, which are susceptible to human error, data manipulation, and significant time delays in detecting temperature excursions.Recent systematic reviews have identified persistent data gaps, limited end-to-end visibility, and high loss-to-specification rates as key bottlenecks undermining vaccine potency and public health outcomes.This paper proposes and evaluates a hybrid system that couples low-power Internet of Things (IoT) temperature sensors with a lightweight blockchain ledger-specifically Hyperledger Besu operating under a Proof-of-Authority (PoA) consensus mechanism-to record every temperature reading in a tamper-proof, time-stamped, and cryptographically verifiable format.The proposed architecture comprises four layers: (i) a hardware layer featuring DS18B20 digital temperature sensors interfaced with ESP32 microcontrollers communicating over LoRaWAN /LPWAN gateways; (ii) an edge-computing layer built on Raspberry Pi 4 nodes running lightweight Docker containers that aggregate sensor data, encrypt it using AES-256 encryption, and generate Merkle proofs; (iii) a blockchain layer where each encrypted data hash and its corresponding timestamp are immutably recorded on the distributed ledger; and (iv) a public-key-based access layer that exposes RESTful APIs secured by OAuth 2.0 and real-time dashboards built on Grafana and Prometheus, allowing authorized stakeholders-including state health departments, auditors, and vaccine manufacturers-to monitor cold-chain integrity in real time.A comprehensive cost-benefit analysis using a net present value (NPV) model over a five-year horizon with an 8% discount rate projects that nationwide roll-out across India's approximately 27,000 cold-chain points would require an estimated capital expenditure of ₹300 million and annual operational expenditure of ₹50 million, while yielding net savings of approximately ₹1.2 billion in reduced vaccine wastage within the first two years.The study thus demonstrates that blockchain-enabled IoT tracking not only improves auditability and reduces vaccine losses but also provides scalable, interoperable, and economically viable infrastructure for India's evolving vaccine logistics ecosystem.Policy recommendations include integration with the Ministry of Health and Family Welfare's electronic Vaccine Intelligence Network (eVIN) and incentive structures for private cold-chain operators to adopt such systems.