On Tue, Jun 14, 2022 at 07:53:29AM -0400, Undiscussed Horrific Abuse, One Victim of Many via bitcoin-dev wrote: > I was privately asked for more opinions. I am sharing them publicly below: > > It's always been clear that OTS proves longness of duration but not > shortness. It doesn't demonstrate that an earlier work was not > published, because it hashes each document hash with private material > the author must separately publicize. Any unpublished private material > could be an earlier equivalent to a public proof. > > the reason i call this 'designed to be broken' is that it lets people > rewrite history to their stories by republishing other people's > documents under different contexts. See "What Can and Can't Timestamps Prove?": https://petertodd.org/2016/opentimestamps-announcement#what-can-and-cant-timestamps-prove OpenTimestamps makes a trade-off: timestamps have significant limitations as to what they're able to prove. But in exchange, they have exceptionally good scalability, making them essentially free to use. Timestamps are also much easier to add on to existing processes and systems such as Git repositories. Schemes that prove uniqueness require much more engineering and redesign work to actually accomplish anything. -- https://petertodd.org 'peter'[:-1]@petertodd.org