An efficient time-stamping solution for long-term digital archiving

Long-term archiving of digital data is necessary to meet many legal requirements. For example, hospitals in many countries must keep health records of patients for decades. Archiving usually relies on digital signatures and time-stamps to prove the security properties of archived data, such as integrity and proof of existence. Moreover, archived data often needs to be updated, e.g. a new prescription is added to a patient´s record, but without compromising integrity and proof of existence. To date, a solution that guarantees integrity and proof of existence indefinitely and allows for updates on archived data is Content Integrity Service (CIS). In this paper, we introduce an improved version of CIS named Content Integrity Service with Skip Lists (CISS) that changes the time-stamping process of CIS by using two different types of time-stamps together with skip lists. We demonstrate that CISS outperforms CIS by analyzing the algorithms and running experiments in realistic scenarios.