Yeah, at this point you might as well hook in to the RecentChanges API, monitor that, sign everything, and then you could detect when there was a RevDel or Oversight action taken and the edit disappears from view.

Or you could, you know, get involved in the WP community and become an Administrator, and then you would actually have access to see those deleted edits and files without hindrance.

This whole bit seems to be some kind of hedge against Wikidata oversighters becoming evil and "covering up" some misdeeds or truths by abusing their powers to delete and suppress edits. While anything could happen, and I grant that this is a temptation to anyone, "signing an integer" as is proposed, with a completely unrelated identity in a completely unrelated PKI, is going to be utterly pointless and won't produce the accountability they seem to seek.

Also, if this signature isn't recorded on the blonkchain, then where is it going to be recorded? Wikidata ain't holding it for you. You've got to put it somewhere. Are you going to use IPFS or Dropbox or something?