Certified time stamps for proof of existence #11
Description
In keeping track of the evolution of digital artifacts, it is a beneficial property to know when something has been created, and that this statement can be trusted. While a bullet-proof proof-of-creation seems to be philosophically impossible to implement, a proof-of-existence at a specific time is possible. To this end, one can send a cryptographic fingerprint uniquely associated with a digital object to a trusted authority that issues a certified timestamp linked to the fingerprint and therefore also the digital object.
In this approach, one still relies on a central authority that must also be trusted. The bitcoin blockchain and similar blockchains offers another mechanism that relies on the immutability of the chain and the method of establishing consensus, making it practically impossible to re-write history. This idea is implemented and explained at https://opentimestamps.org/
It would be a nice addition if a JsonGraphNode can be timestamped in this way during creation.