Subject: Re: [Bitcoin-development] 32 vs 64-bit timestamp fields

From: John Dillon <[email-masked]>
Date: Thu, 9 May 2013 01:27:33 +0000

On Thu, May 9, 2013 at 1:13 AM, Pieter Wuille <[email-masked]> wrote:
> On Wed, May 08, 2013 at 09:08:34PM -0400, Jeff Garzik wrote:
>> Guffaw :)  The year 2038 is so far in the future that it is not really
>> relevant, from that angle.
>
> "Meh". I think it's highly unlikely we'll break the block header format, as it
> pretty much means invalidating all mining hardware.

Doesn't most mining hardware at the ASCI level start with a SHA256 midstate
given that the nonce is at the end?  Adding further information to the block
should be possible at the beginning of the block without major changes to the
mining hardware.

> There's also no need: 32 bits is plenty of precision. Hell, even 16 bits would
> do (assuming there's never more than a 65535s (about 18 hours) gap between two
> blocks). Just assume the "full" 64-bit time is the smallest one that makes
> sense, given its lower 32 bits.

I feel somewhat uncomfortable about the "after-the-fact" auditing possible in
this scenario. Besides the timestamping provided by the block headers appears
to be useful in some payment protocols, not to mention in general.