A blockchain-based infection tracing and notification system by non-fungible tokens

SARS-CoV2 pandemic is heavily affecting our lives. Many actions have been undertaken to slow down its expansion and, among the others, contact tracing applications are the less invasive to monitor the spread of the virus. The idea behind contact tracing is to track contacts between people by the exchange of identifiers, not linked to individuals, exploiting the use of Bluetooth Low Energy (BLE) technology to estimate the duration and proximity of contacts. The data collected in this way is used for the sole purpose of notifying a potential contact with an infected person without revealing their identity and location. This paper presents a contact tracing protocol based on blockchain technology that exploits smart contracts for reporting contacts at risk of contagion. The novelty of the proposed solution is the use of Non Fungible Tokens (NFT) to guarantee user privacy through a decentralized approach, equipped with a reliable non-proprietary notification mechanism that allows public access to anonymous infections data.