{"parentHash":null,"text":"After the edit window closes on a post/comment, we now timestamp posts/comments in the timechain using [OpenTimestamps](https://opentimestamps.org/). The resulting proof allows stackers to know a piece of content is at least as old as the bitcoin block that it's in. While maybe not super or immediately useful for SN, it's pretty cool.\n\nThis only applies to content created from this point forward so long as it's a post or the child of a post that's been timestamped. We might at some point timestamp historical content but we don't yet. We also don't upgrade timestamps to be independently verifiable, instead relying on the calendars we submitted the hashes to.\n\nHow this works: \n1. After the edit window closes, we sha256 hash a canonical json object of the post/comment.\n     - the preimages of comments include the hash of their parent\n2. We then send this hash to OTS for timestamping.\n3. At this point, you can view the OTS info by appending `/ots` to the item's path\n    - if you attempt to view the OTS info before we've submitted the timestamp or on a piece of content that wasn't timestamped, you'll 404\n    - because when we delete items we actually delete them, the preimage is not available on deleted items ... however, the hash and the resulting timestamp is kept\n4. You can download both the preimage and the ots file and verify the timestamp for yourself.\n\nWe might at some point make it easier to see the ots info, but for now you'll need to do the url stuff.\n\nAssuming the edit window on this post has closed, [you can view the timestamp](/items/125552/ots).\n","title":"SN release: OpenTimestamps timestamps","url":null}