Subject: Re: [bitcoin-dev] Why OpenTimestamps does not "linearize" its transactions

From: Peter Todd <[email-masked]>
Date: Tue, 14 Jun 2022 11:22:21 -0400

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 Any unpublished private material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