Feature: verified timestamp of data

At ODIN2025, @bil-paul presented their timestamping project: https://github.com/bil/timestamping

The idea is to ensure data has not been tampered with to artificially manufacture findings. The package uses SSL and a checksum of data files to verify that the state of data was identical at a specific past time. This can be done with a certificate file managed by the lab, and can also be verified with a central registry managed by them. The idea is to be able to say "this data was not tampered with after time X" even when that time is before the data was shared. (@bil-paul, this is from my memory of your talk. Please correct me if I am off on the details).

I wanted to open this ticket to discuss whether / how this could be integrated with DANDI. For example, we could allow users to upload the certificate files, or we could make API calls to the registry to confirm a data integrity date. We could provide this data integrity date for each asset as asset-level metadata, and we could also provide a date for the dandiset as a whole (the max of the dates of the assets) and add a badge to the dandiset landing page. When an asset is uploaded to DANDI, DANDI could automatically call the timestamping REST API, if the data had not previously been registered, it will be now, and we can provide the current datetime as the verified date. If it has been previously registered, we can use that date instead.

I don't know of any other scientific data archive that is doing this, so it would really push DANDI to SOTA in terms of scientific rigor.

@waxlamp , I'd be interested to hear your take on this

The issue names no files, tests, or entry points. Begin by determining whether DANDI should support certificate uploads, registry API verification, or automatic timestamp registration, then define how verified dates apply to assets and dandisets and what the landing-page badge should display.