International Association
for Cryptologic Research

Digital archives that store electronic data for long periods are increasingly necessary for applications such as libraries, land registers, and medical records. Archived data is useful if protected from tampering to ensure authenticity, integrity and a date on which the existence of archived data was witnessed. We survey solutions that protected archived data using cryptography. We describe them and verify whether they successfully provide indefinite protection despite of current cryptography schemes\' limitations. Solutions are compared in regard to their goals, trust assumptions and efficiency. Based on our analysis, we elucidate open problems and promising research directions.