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From: Gregory Maxwell <greg@xiph•org>
To: Sergio Demian Lerner <sergio.d.lerner@gmail•com>
Cc: bitcoin-dev <bitcoin-dev@lists•linuxfoundation.org>, hello@p2sh•info
Subject: Re: [bitcoin-dev] Some real-world results about the current Segwit Discount
Date: Mon, 8 May 2017 23:56:49 +0000	[thread overview]
Message-ID: <CAAS2fgTMi8V3NsaueR72Ewy1V3C0PUvuR7Sv-kgS=oz7oiuSTA@mail.gmail.com> (raw)
In-Reply-To: <CAKzdR-qojNn8OtUTPbxa0JauK9nmo2ZGm4ihKuyzsz_FAgokDw@mail.gmail.com>

On Mon, May 8, 2017 at 10:42 PM, Sergio Demian Lerner via bitcoin-dev
<bitcoin-dev@lists•linuxfoundation.org> wrote:
> The non-witness data weight factor should not be 4 but 2.35. The closest
> integer value is 2, which leads to a 50% witness discount.

Sergio, You've provided absolutely no information to qualify your
"should be".  It sounds like you are only measuring how much data is
witness vs non-witness while completely ignoring the relative cost of
UTXO bloat?  It's perfectly acceptable to increase the worst case in
one dimension while decreasing it in another-- and thats what segwit
does.

This sounds like a misunderstanding of what the factors should have
accomplish. The non-witness factor should be as large as possible
because the prunable witness data has little to no long term cost to
the system, no cost to lite clients, etc-- as eventually the system's
survival will require transitioning to starting from a state snapshot.
But it cannot be too large because of the hyperbolic increase in worst
case bandwidth.   Also, when starting from a state snapshot security
will require starting from an old one-- otherwise the whole system
becomes much closer to SPV security, so the cost of witness data
between there and the tip will still matter.

If I had any leaning to adjust it, it would be towards five-- not
towards even lower values.

> The Bitcoinj source code is available for anyone to review.

Where is it? (I have to say, I haven't found bitcoinj based things at
all readable but it would be worth seeing.)


      parent reply	other threads:[~2017-05-08 23:56 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-08 22:42 Sergio Demian Lerner
2017-05-08 23:47 ` Alphonse Pace
2017-05-09 13:49   ` Sergio Demian Lerner
2017-05-09 14:33     ` James Hilliard
2017-05-09 15:45     ` Johnson Lau
2017-05-09 16:19       ` Sergio Demian Lerner
2017-05-09 16:27         ` Johnson Lau
2017-05-09 16:27         ` James Hilliard
2017-05-09 18:15     ` Matt Corallo
2017-05-09 18:58       ` Sergio Demian Lerner
2017-05-09 19:15         ` Sergio Demian Lerner
2017-05-09 19:30           ` Gregory Maxwell
2017-05-09 19:42             ` Matt Corallo
2017-05-09 20:13               ` Gregory Maxwell
2017-05-09 20:58                 ` Sergio Demian Lerner
2017-05-10  5:37                   ` Jorge Timón
2017-05-10 14:05                   ` Matt Corallo
2017-05-10 15:25                     ` Sergio Demian Lerner
2017-05-10 16:39                       ` Matt Corallo
2017-05-10 19:40                         ` Sergio Demian Lerner
2017-05-08 23:56 ` Gregory Maxwell [this message]

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