SecureABC: Secure AntiBody Certificates for COVID-19

COVID-19 has resulted in unprecedented social distancing policies being enforced worldwide. As governments urgently seek to reopen society, there is a demand for technologies that may alleviate the requirement for social distancing whilst also protecting healthcare services and maintaining human and civil rights. In this work we explore the controversial technique of so-called immunity passports and present SecureABC: a decentralised, privacy-preserving system for issuing and verifying antibody certificates. We consider the implications of immunity passport systems, develop a set of general principles and security requirements for their deployment and show that these may be satisfied in practice.