I'm not sure if it counts as a "block" "chain", but I'm using a chain of hashes to verify integrity of an online message board, so that you can more easily veri

I'm not sure if it counts as a "block" "chain", but I'm using a chain of hashes to verify integrity of an online message board, so that you can more easily verify that you are all seeing the same conversation thread. And if any messages are deleted, everyone can see that something was there, and when it was deleted, and who deleted it.