A Timestamping Scheme with Eternal Security in the Bounded Storage Model

Digital timestamping is a cryptographic technique allowing affixing a reliable date to a digital document. The security of most existing timestamping systems is based on the security of the used cryptographic techniques as hash functions. However, a hash function has a limited lifetime. In this context, we provide a non-interactive timestamping scheme in the bounded storage model (BSM) whose security is not related to the life of any cryptographic technique. We prove, in fact, that our timestamping scheme is eternally secure even against an adversary with unlimited computing power.