LTPS - Service for long-term preservation of digital signatures

Digital transformation of public or private services, although it brings many improvements for our societies, it also raises security issues, mainly when focusing on the migration of physical signed documents in the digital environment. Digital signatures have proven to be reliable, thus they have seen a higher adoption in the last few years, especially in the context of the Covid-19 pandemic. Yet, a disadvantage is that digital signatures are volatile, being valid only for a maximum of a few years, depending on the validity of the asymmetric private key used to create that digital signature. Thus, validating a signed document after a few years could prove to be troublesome. In order to solve this problem, legislative and standardization efforts have been made and the legal and technical frameworks for long-term preservation services have been issued. In this paper we focus on the presentation of our implementation of a long-term preservation service for digital signatures, that is part of an entire long-term preservation system composed of multiple services, as mentioned in the paper. Our implementation is compliant with ETSI standards and uses the capabilities of current PKI infrastructures, while also adding in the resilience and trust of the blockchain.