Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 087F48D4 for ; Fri, 20 Oct 2017 17:24:37 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-it0-f51.google.com (mail-it0-f51.google.com [209.85.214.51]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 8F0161AD for ; Fri, 20 Oct 2017 17:24:35 +0000 (UTC) Received: by mail-it0-f51.google.com with SMTP id 72so14791802itl.5 for ; Fri, 20 Oct 2017 10:24:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=PPgcmoJtoJdc1+xF9s7U6dmbV7qMOxlCzrrRqy6Stkg=; b=YX9wrB7vbsrGVFbqW4Txpj5WXaQawXW/92efv8lRWpsJOiUxbnLDMdElnuYhHP8H0/ PLWGnqSLqIDCxeZD+s33Q0bnBbgItOrrFM3dkUdXwj/xmIzUq4E3MUj0N9Mf4OfuC59L CSzmax8U/JUclht+8PGSobLmk96oV7bG6Qu2CECyPtmhh16Yj3TndwHVQXqL2fLel8f0 5wwspyQRkUsm0QPC3VG/q1t5On0E+/Jtw+mGGIFHVBBAL4xbHr7AfLPf4v0fRGqgPPvA j/S8ocy+JRrseZ2ZbXrTIKJ4l3EPopqvauVZ080GCKfqWkGsYPC6GdcPFQ6no3DZYlsU 5e9A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=PPgcmoJtoJdc1+xF9s7U6dmbV7qMOxlCzrrRqy6Stkg=; b=mK4DSEJBGnSSfWbIbypvCp8JI0lLLICEfsfU0wNlPT7qj5YOoR7wzl7UE6uX21u5PQ /NbIY+nXacC6qpfuZxtsuADxWaq7Lxr3vgxeZuk0txUmUz+tzZmSaB6pC+BVy2MK6G0h ga+GLd/7spWCaBiXueAcESfqz2a1t3eKvP2AHetwpurCbVSmM6ceEoZVIKZrdT69fwyw y0ex+bMqen+s2plfJNXOY/qeKc7kscheKHF90uJAd2SnDwcWVWI9hxSlYEc+w9lhqJoJ foNS1Po07g2M19IOWjAUoSanNrSOQA1Zg7T61zyCLC4jlyn9tjqiHH/eR6mPHrTongR0 v8cg== X-Gm-Message-State: AMCzsaVI22JSC5uwXMSCb7+wXQ3OSzsk9NPh7NFIldzHzjHww8AV7w2u L+AZq01bK9KVvuFNNxjEKq41rwZq4Lurv/8S5QI= X-Google-Smtp-Source: ABhQp+Sji1HE51gGQ4A8/ig/RUs3Gnlwj1MDNd+mMN1OAsZopUpfFVgrY2iXnQz5Zoujwmpqbz0ljEgb4gBsTGAc9Xo= X-Received: by 10.36.245.11 with SMTP id k11mr3773177ith.0.1508520274608; Fri, 20 Oct 2017 10:24:34 -0700 (PDT) MIME-Version: 1.0 Received: by 10.2.28.135 with HTTP; Fri, 20 Oct 2017 10:24:34 -0700 (PDT) Received: by 10.2.28.135 with HTTP; Fri, 20 Oct 2017 10:24:34 -0700 (PDT) In-Reply-To: References: From: Ilan Oh Date: Fri, 20 Oct 2017 19:24:34 +0200 Message-ID: To: bitcoin-dev@lists.linuxfoundation.org Content-Type: multipart/alternative; boundary="94eb2c035dba1ac576055bfdbf92" X-Spam-Status: No, score=0.4 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FROM,HTML_MESSAGE,RCVD_IN_DNSWL_NONE, RCVD_IN_SORBS_SPAM autolearn=disabled version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org X-Mailman-Approved-At: Fri, 20 Oct 2017 17:33:23 +0000 Subject: Re: [bitcoin-dev] bitcoin-dev Digest, Vol 29, Issue 24 X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Protocol Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 20 Oct 2017 17:24:37 -0000 --94eb2c035dba1ac576055bfdbf92 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable The only blocktime reduction that would be a game changer, would be a 1 second blocktime or less, and by less I mean much less maybe 1000 blocks/second. Which would enable decentralized high frequency trading or playing WoW on blockchain and other cool stuff. But technology is not developped enough as far as I now, maybe with quantum computers in the future, and it is even bitcoins goal? Also there is a guy who wrote a script to avoid "sybil attack" from 2x https://github.com/mariodian/ban-segshit8x-nodes I don't know what it's worth, maybe check it out, I'm not huge support of that kind of methods. Ilansky Le 20 oct. 2017 14:01, a =C3=A9crit : > Send bitcoin-dev mailing list submissions to > bitcoin-dev@lists.linuxfoundation.org > > To subscribe or unsubscribe via the World Wide Web, visit > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev > or, via email, send a message with subject or body 'help' to > bitcoin-dev-request@lists.linuxfoundation.org > > You can reach the person managing the list at > bitcoin-dev-owner@lists.linuxfoundation.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of bitcoin-dev digest..." > > > Today's Topics: > > 1. Improving Scalability via Block Time Decrease (Jonathan Sterling) > 2. Re: Improving Scalability via Block Time Decrease > (=3D?UTF-8?Q?Ad=3Dc3=3Da1n_S=3Dc3=3Da1nchez_de_Pedro_Crespo?=3D) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Thu, 19 Oct 2017 14:52:48 +0800 > From: Jonathan Sterling > To: bitcoin-dev@lists.linuxfoundation.org > Subject: [bitcoin-dev] Improving Scalability via Block Time Decrease > Message-ID: > gmail.com> > Content-Type: text/plain; charset=3D"utf-8" > > The current ten-minute block time was chosen by Satoshi as a tradeoff > between confirmation time and the amount of work wasted due to chain > splits. Is there not room for optimization in this number from: > > A. Advances in technology in the last 8-9 years > B. A lack of any rigorous formula being used to determine what's the > optimal rate > C. The existence of similar chains that work at a much lower block times > > Whilst I think we can all agree that 10 second block times would result i= n > a lot of chain splits due to Bitcoins 12-13 second propagation time (to 9= 5% > of nodes), I think we'll find that we can go lower than 10 minutes withou= t > much issue. Is this something that should be looked at or am I an idiot w= ho > needs to read more? If I'm an idiot, I apologize; kindly point me in the > right direction. > > Things I've read on the subject: > https://medium.facilelogin.com/the-mystery-behind-block-time-63351e35603a > (section header "Why Bitcoin Block Time Is 10 Minutes ?") > https://bitcointalk.org/index.php?topic=3D176108.0 > https://bitcoin.stackexchange.com/questions/1863/why-was- > the-target-block-time-chosen-to-be-10-minutes > > Kind Regards, > > Jonathan Sterling > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: attachments/20171019/d940fd4e/attachment-0001.html> > > ------------------------------ > > Message: 2 > Date: Thu, 19 Oct 2017 15:41:51 +0200 > From: "=3D?UTF-8?Q?Ad=3Dc3=3Da1n_S=3Dc3=3Da1nchez_de_Pedro_Crespo?=3D" > > To: bitcoin-dev@lists.linuxfoundation.org > Subject: Re: [bitcoin-dev] Improving Scalability via Block Time > Decrease > Message-ID: <40b6ef7b-f518-38cd-899a-8f301bc7ac3a@stampery.com> > Content-Type: text/plain; charset=3Dutf-8 > > Blockchains with fast confirmation times are currently believed to > suffer from reduced security due to a high stale rate. > > As blocks take a certain time to propagate through the network, if miner > A mines a block and then miner B happens to mine another block before > miner A's block propagates to B, miner B's block will end up wasted and > will not "contribute to network security". > > Furthermore, there is a centralization issue: if miner A is a mining > pool with 30% hashpower and B has 10% hashpower, A will have a risk of > producing a stale block 70% of the time (since the other 30% of the time > A produced the last block and so will get mining data immediately) > whereas B will have a risk of producing a stale block 90% of the time. > > Thus, if the block interval is short enough for the stale rate > to be high, A will be substantially more efficient simply by virtue of > its size. With these two effects combined, blockchains which produce > blocks quickly are very likely to lead to one mining pool having a large > enough percentage of the network hashpower to have de facto control over > the mining process. > > Another possible implication of reducing the average block time is that > block size should be reduced accordingly. In an hypothetical 5 minutes > block size Bitcoin blockchain, there would be twice the block space > available for miners to include transactions, which could lead to 2 > immediate consequences: (1) the blockchain could grow up to twice the > rate, which is known to be bad for decentralization; and (2) transaction > fees might go down, making it cheaper for spammers to bloat our beloved > UTXO sets. > > There have been numerous proposals that tried to overcome the downsides > of faster blocks, the most noteworthy probably being the "Greedy > Heaviest Observed Subtree" (GHOST) protocol: > http://www.cs.huji.ac.il/~yoni_sompo/pubs/15/btc_scalability_full.pdf > > Personally, I can't see why Bitcoin would need or how could it even > benefit at all from faster blocks. Nevertheless, I would really love if > someone in the list who has already run the numbers could bring some > valid points on why 10 minutes is the optimal rate (other than "if it > ain't broke, don't fix it"). > > -- > Ad?n S?nchez de Pedro Crespo > CTO, Stampery Inc. > San Francisco - Madrid > > > ------------------------------ > > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev > > > End of bitcoin-dev Digest, Vol 29, Issue 24 > ******************************************* > --94eb2c035dba1ac576055bfdbf92 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
The only blocktime reduction that would be a game changer= , would be a 1 second blocktime or less, and by less I mean much less maybe= 1000 blocks/second. Which would enable decentralized high frequency tradin= g or playing WoW on blockchain and other cool stuff.=C2=A0

But technology is not developped enough as far= as I now, maybe with quantum computers in the future, and it is even bitco= ins goal?

Also there is = a guy who wrote a script to avoid "sybil attack" from 2x
https://github.com/mariodian/ban-segshit8x-nodes

I don't know what it's worth, may= be check it out, I'm not huge support of that kind of methods.

Ilansky
<= br>

Le= =C2=A020 oct. 2017 14:01, <bitcoin-dev-request@lists.linux= foundation.org> a =C3=A9crit=C2=A0:
Send bitcoin-dev mailing list submissions to
=C2=A0 =C2=A0 =C2=A0 =C2=A0 bitcoin-dev@lists.linuxfoundation.org

To subscribe or unsubscribe via the World Wide Web, visit
=C2=A0 =C2=A0 =C2=A0 =C2=A0 https://li= sts.linuxfoundation.org/mailman/listinfo/bitcoin-dev
or, via email, send a message with subject or body 'help' to
=C2=A0 =C2=A0 =C2=A0 =C2=A0 bitcoin-dev-request@lists.linuxfoundation.org
You can reach the person managing the list at
=C2=A0 =C2=A0 =C2=A0 =C2=A0 bitcoin-dev-owner@lists.linuxfoundation.org

When replying, please edit your Subject line so it is more specific
than "Re: Contents of bitcoin-dev digest..."


Today's Topics:

=C2=A0 =C2=A01. Improving Scalability via Block Time Decrease (Jonathan Ste= rling)
=C2=A0 =C2=A02. Re: Improving Scalability via Block Time Decrease
=C2=A0 =C2=A0 =C2=A0 (=3D?UTF-8?Q?Ad=3Dc3=3Da1n_S=3Dc3=3Da1nchez_de_Pe= dro_Crespo?=3D)


-----------------------------------------------------------------= -----

Message: 1
Date: Thu, 19 Oct 2017 14:52:48 +0800
From: Jonathan Sterling <jon@thanco= des.com>
To: bitcoin-dev@li= sts.linuxfoundation.org
Subject: [bitcoin-dev] Improving Scalability via Block Time Decrease
Message-ID:
=C2=A0 =C2=A0 =C2=A0 =C2=A0 <CAH01uEtLhLEj5XOp_MDRii2dR8-zUu4fUsCd25mzLDtpD_fwYQ@mail.gmail.com>
Content-Type: text/plain; charset=3D"utf-8"

The current ten-minute block time was chosen by Satoshi as a tradeoff
between confirmation time and the amount of work wasted due to chain
splits. Is there not room for optimization in this number from:

A. Advances in technology in the last 8-9 years
B. A lack of any rigorous formula being used to determine what's the optimal rate
C. The existence of similar chains that work at a much lower block times
Whilst I think we can all agree that 10 second block times would result in<= br> a lot of chain splits due to Bitcoins 12-13 second propagation time (to 95%=
of nodes), I think we'll find that we can go lower than 10 minutes with= out
much issue. Is this something that should be looked at or am I an idiot who=
needs to read more? If I'm an idiot, I apologize; kindly point me in th= e
right direction.

Things I've read on the subject:
https://medium.facilelogin.= com/the-mystery-behind-block-time-63351e35603a
(section header "Why Bitcoin Block Time Is 10 Minutes ?")
https://bitcointalk.org/index.php?topic=3D176= 108.0
https://bitcoin.stackexchange.com/questions/1863/why-was-the-ta= rget-block-time-chosen-to-be-10-minutes

Kind Regards,

Jonathan Sterling
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.linuxfoundation.org/pipermail/bitcoin-dev/<= wbr>attachments/20171019/d940fd4e/attachment-0001.html>

------------------------------

Message: 2
Date: Thu, 19 Oct 2017 15:41:51 +0200
From: "=3D?UTF-8?Q?Ad=3Dc3=3Da1n_S=3Dc3=3Da1nchez_de_Pedro_Crespo= ?=3D"
=C2=A0 =C2=A0 =C2=A0 =C2=A0 <adan@st= ampery.co>
To: bitcoin-dev@li= sts.linuxfoundation.org
Subject: Re: [bitcoin-dev] Improving Scalability via Block Time
=C2=A0 =C2=A0 =C2=A0 =C2=A0 Decrease
Message-ID: <40b6ef7b-f518-38cd-899a-8f301bc7ac3a@stampery.com> Content-Type: text/plain; charset=3Dutf-8

Blockchains with fast confirmation times are currently believed to
suffer from reduced security due to a high stale rate.

As blocks take a certain time to propagate through the network, if miner A mines a block and then miner B happens to mine another block before
miner A's block propagates to B, miner B's block will end up wasted= and
will not "contribute to network security".

Furthermore, there is a centralization issue: if miner A is a mining
pool with 30% hashpower and B has 10% hashpower, A will have a risk of
producing a stale block 70% of the time (since the other 30% of the time A produced the last block and so will get mining data immediately)
whereas B will have a risk of producing a stale block 90% of the time.

Thus, if the block interval is short enough for the stale rate
to be high, A will be substantially more efficient simply by virtue of
its size. With these two effects combined, blockchains which produce
blocks quickly are very likely to lead to one mining pool having a large enough percentage of the network hashpower to have de facto control over the mining process.

Another possible implication of reducing the average block time is that
block size should be reduced accordingly. In an hypothetical 5 minutes
block size Bitcoin blockchain, there would be twice the block space
available for miners to include transactions, which could lead to 2
immediate consequences: (1) the blockchain could grow up to twice the
rate, which is known to be bad for decentralization; and (2) transaction fees might go down, making it cheaper for spammers to bloat our beloved
UTXO sets.

There have been numerous proposals that tried to overcome the downsides
of faster blocks, the most noteworthy probably being the "Greedy
Heaviest Observed Subtree" (GHOST) protocol:
http://www.cs.huji.ac.il/~= yoni_sompo/pubs/15/btc_scalability_full.pdf

Personally, I can't see why Bitcoin would need or how could it even
benefit at all from faster blocks. Nevertheless, I would really love if
someone in the list who has already run the numbers could bring some
valid points on why 10 minutes is the optimal rate (other than "if it<= br> ain't broke, don't fix it").

--
Ad?n S?nchez de Pedro Crespo
CTO, Stampery Inc.
San Francisco - Madrid


------------------------------

_______________________________________________
bitcoin-dev mailing list
bitcoin-dev@lists.= linuxfoundation.org
https://lists.linuxfoundation.org= /mailman/listinfo/bitcoin-dev


End of bitcoin-dev Digest, Vol 29, Issue 24
*******************************************
--94eb2c035dba1ac576055bfdbf92--