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In-Reply-To: <55994696.1090705@thinlink.com>
References: <55994696.1090705@thinlink.com>
Date: Sun, 5 Jul 2015 09:17:19 -0700
Message-ID: <CAOG=w-sgM+H0bGBfZxLhbUHF3y=v4vdBAOTDsZ1LEc3dLzsf6g@mail.gmail.com>
From: Mark Friedenbach <mark@friedenbach.org>
To: Tom Harding <tomh@thinlink.com>
Content-Type: multipart/alternative; boundary=20cf303f64ca9b42b3051a231f0b
Cc: bitcoin-dev@lists.linuxfoundation.org
Subject: Re: [bitcoin-dev] BIP 68 (Relative Locktime) bug
Precedence: list

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Can you construct an example? Are there use cases where there is a need for
an enforced lock time in a transaction with inputs that are not confirmed
at the time the lock time expires?
On Jul 5, 2015 8:00 AM, "Tom Harding" <tomh@thinlink.com> wrote:

> BIP 68 uses nSequence to specify relative locktime, but nSequence also
> continues to condition the transaction-level locktime.
>
> This dual effect will prevent a transaction from having an effective
> nLocktime without also requiring at least one of its inputs to be mined
> at least one block (or one second) ahead of its parent.
>
> The fix is to shift the semantics so that nSequence = MAX_INT - 1
> specifies 0 relative locktime, rather than 1.  This change will also
> preserve the semantics of transactions that have already been created
> with the specific nSequence value MAX_INT - 1 (for example all
> transactions created by the bitcoin core wallet starting in 0.11).
>
>
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev@lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>

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<p dir=3D"ltr">Can you construct an example? Are there use cases where ther=
e is a need for an enforced lock time in a transaction with inputs that are=
 not confirmed at the time the lock time expires?</p>
<div class=3D"gmail_quote">On Jul 5, 2015 8:00 AM, &quot;Tom Harding&quot; =
&lt;<a href=3D"mailto:tomh@thinlink.com">tomh@thinlink.com</a>&gt; wrote:<b=
r type=3D"attribution"><blockquote class=3D"gmail_quote" style=3D"margin:0 =
0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">BIP 68 uses nSequence=
 to specify relative locktime, but nSequence also<br>
continues to condition the transaction-level locktime.<br>
<br>
This dual effect will prevent a transaction from having an effective<br>
nLocktime without also requiring at least one of its inputs to be mined<br>
at least one block (or one second) ahead of its parent.<br>
<br>
The fix is to shift the semantics so that nSequence =3D MAX_INT - 1<br>
specifies 0 relative locktime, rather than 1.=C2=A0 This change will also<b=
r>
preserve the semantics of transactions that have already been created<br>
with the specific nSequence value MAX_INT - 1 (for example all<br>
transactions created by the bitcoin core wallet starting in 0.11).<br>
<br>
<br>
_______________________________________________<br>
bitcoin-dev mailing list<br>
<a href=3D"mailto:bitcoin-dev@lists.linuxfoundation.org">bitcoin-dev@lists.=
linuxfoundation.org</a><br>
<a href=3D"https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev" =
rel=3D"noreferrer" target=3D"_blank">https://lists.linuxfoundation.org/mail=
man/listinfo/bitcoin-dev</a><br>
</blockquote></div>

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