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Date: Sun, 21 Jun 2015 11:54:07 +0100
Message-ID: <CAE-z3OVgQFaFAWUJhDLzyMAE2AXoGHTy0NbUADDAZW9-veX8XA@mail.gmail.com>
From: Tier Nolan <tier.nolan@gmail.com>
Cc: Bitcoin Dev <bitcoin-development@lists.sourceforge.net>
Content-Type: multipart/alternative; boundary=001a11441460ee31e3051904f99b
Subject: Re: [Bitcoin-development] [BIP draft] Motivation and deployment of
 consensus rules changes ([soft/hard]forks)
Precedence: list

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On Sun, Jun 21, 2015 at 11:31 AM, Jorge Tim=C3=B3n <jtimon@jtimon.cc> wrote=
:

> You mean the timewarp fix can be coded as a softfork instead of a
> hardfork? How so?
>

The easiest would be a rule requiring that all blocks are within 1 day of
the median of the previous 11 blocks.  At the moment, you need to be
greater than that value.  This would add a condition at the other end.

It wouldn't be a total fix, but it would protect against the exploit.

A stricter soft fork would be that the two blocks in question have to have
the same timestamp.  This would force the off by 1 and the correct value to
give the same result.

If that's the case, do you have a better candidate?
>

I think it is fine, since fixing it "right" does require a hard fork,
especially if it is only to show a non controversial hard fork.

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<div dir=3D"ltr"><div class=3D"gmail_extra"><div class=3D"gmail_quote">On S=
un, Jun 21, 2015 at 11:31 AM, Jorge Tim=C3=B3n <span dir=3D"ltr">&lt;<a hre=
f=3D"mailto:jtimon@jtimon.cc" target=3D"_blank">jtimon@jtimon.cc</a>&gt;</s=
pan> wrote:<br><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex=
;border-left:1px #ccc solid;padding-left:1ex"><span>
</span>You mean the timewarp fix can be coded as a softfork instead of a<br=
>
hardfork? How so?<br></blockquote><div><br></div><div>The easiest would be =
a rule requiring that all blocks are within 1 day of the median of the prev=
ious 11 blocks.=C2=A0 At the moment, you need to be greater than that value=
.=C2=A0 This would add a condition at the other end.<br><br></div><div>It w=
ouldn&#39;t be a total fix, but it would protect against the exploit.<br><b=
r></div><div>A stricter soft fork would be that the two blocks in question =
have to have the same timestamp.=C2=A0 This would force the off by 1 and th=
e correct value to give the same result.<br></div><div><br></div><blockquot=
e class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc sol=
id;padding-left:1ex">
If that&#39;s the case, do you have a better candidate?<br>
</blockquote></div><br></div><div class=3D"gmail_extra">I think it is fine,=
 since fixing it &quot;right&quot; does require a hard fork, especially if =
it is only to show a non controversial hard fork.<br></div></div>

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