Framework for a DLT Based COVID-19 Passport
This addresses the problem of privacy-preserving identity verification for individuals during health crises like COVID-19, though it is incremental as it builds on existing blockchain and biometric techniques.
The paper tackles the challenge of securely and privately identifying individuals across networks by proposing a framework for storing COVID-19 vaccination details on a blockchain, using a two-factor authentication system with biometric cryptographic hashing to generate unique identifiers without leaking personal information.
Uniquely identifying individuals across the various networks they interact with on a daily basis remains a challenge for the digital world that we live in, and therefore the development of secure and efficient privacy preserving identity mechanisms has become an important field of research. In addition, the popularity of decentralised decision making networks such as Bitcoin has seen a huge interest in making use of distributed ledger technology to store and securely disseminate end user identity credentials. In this paper we describe a mechanism that allows one to store the COVID-19 vaccination details of individuals on a publicly readable, decentralised, immutable blockchain, and makes use of a two-factor authentication system that employs biometric cryptographic hashing techniques to generate a unique identifier for each user. Our main contribution is the employment of a provably secure input-hiding, locality-sensitive hashing algorithm over an iris extraction technique, that can be used to authenticate users and anonymously locate vaccination records on the blockchain, without leaking any personally identifiable information to the blockchain.