Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193] helo=mx.sourceforge.net) by sfs-ml-2.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1YPEwQ-0007l3-DW for bitcoin-development@lists.sourceforge.net; Sat, 21 Feb 2015 18:38:14 +0000 Received-SPF: pass (sog-mx-3.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.218.47 as permitted sender) client-ip=209.85.218.47; envelope-from=ctpacia@gmail.com; helo=mail-oi0-f47.google.com; Received: from mail-oi0-f47.google.com ([209.85.218.47]) by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1YPEwN-0005bx-9X for bitcoin-development@lists.sourceforge.net; Sat, 21 Feb 2015 18:38:14 +0000 Received: by mail-oi0-f47.google.com with SMTP id i138so7684390oig.6 for ; Sat, 21 Feb 2015 10:38:05 -0800 (PST) X-Received: by 10.202.197.204 with SMTP id v195mr2248170oif.54.1424543885485; Sat, 21 Feb 2015 10:38:05 -0800 (PST) MIME-Version: 1.0 References: <54E8AC69.4000102@gmail.com> From: Chris Pacia Date: Sat, 21 Feb 2015 18:38:05 +0000 Message-ID: To: Mike Hearn Content-Type: multipart/alternative; boundary=001a1134e2d842ed51050f9d78df X-Spam-Score: -0.6 (/) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -1.5 SPF_CHECK_PASS SPF reports sender host as permitted sender for sender-domain 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (ctpacia[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 1.0 HTML_MESSAGE BODY: HTML included in message -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature X-Headers-End: 1YPEwN-0005bx-9X Cc: Bitcoin Dev Subject: Re: [Bitcoin-development] bloom filtering, privacy X-BeenThere: bitcoin-development@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 21 Feb 2015 18:38:14 -0000 --001a1134e2d842ed51050f9d78df Content-Type: text/plain; charset=UTF-8 Yeah that overhead is pretty high. I wasn't thinking about 10 years out. On Sat, Feb 21, 2015, 11:47 AM Mike Hearn wrote: > Adam seems to be making sense to me. Only querying a single node when an >> address in my wallet matches the block filter seems to be pretty efficient. >> > > No, I think it's less efficient (for the client). > > Quick sums: blocks with 1500 transactions in them are common today. But > Bitcoin is growing. Let's imagine a system 10x larger than today. Doesn't > seem implausible to reach that in the next 5-10 years, so 15,000 > transactions. Each transaction has multiple elements we might want to match > (addresses, keys, etc). > > Let's say the average tx contains 5 unique keys/elements. That's the base > case of {1 input, 2 outputs} without address reuse, plus fudged up a bit > for multi-sends then down a bit again for address reuse. > > 15,000*5=75,000 unique elements per block. With an FP rate of 0.1% we get: > > http://hur.st/bloomfilter?n=75000&p=0.001 > > 131.63KB per block extra overhead. > > 144 blocks in a day, so that's 18mb of data per day's worth of sync to > pull down over the network. If you don't start your wallet for a week > that's 126 megabytes of data just to get started. > > Affordable, yes (in the west). Fast enough to be competitive? Doubtful. I > don't believe that even in five years mobiles will be pulling down and > processing that much data within a few seconds, not even in developed > countries. > > But like I said, I don't see why it matters. Anyone who is watching the > wire close to you learns which transactions are yours, still, so it doesn't > stop intelligence agencies. Anyone who is running a node learns which > transactions in the requested block were yours and thus can follow the tx > chain to learn which other transactions might be yours too, no different to > today. If you connect to a single node and say "give me the transactions > sending money to key A in block N", it doesn't matter if you then don't > request block N+6 from the same peer - they know you will request it > eventually anyway, just by virtue of the fact that one of the transactions > they gave you was spent in that block. > > > --001a1134e2d842ed51050f9d78df Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable

Yeah that overhead is pretty high. I wasn't thinking abo= ut 10 years out.


On Sat, Feb 21, 2015, 11:47 AM=C2=A0Mike Hea= rn <mike@plan99.net> wrote:
Adam seems to be making sense to me. Only querying a single no= de when an address in my wallet matches the block filter seems to be pretty efficient.

N= o, I think it's less efficient (for the client).

Quick sums: =C2=A0blocks with 1500 transactions in them are common today= . But Bitcoin is growing. Let's imagine a system 10x larger than today.= Doesn't seem implausible to reach that in the next 5-10 years, so 15,0= 00 transactions. Each transaction has multiple elements we might want to ma= tch (addresses, keys, etc).=C2=A0

Let's say th= e average tx contains 5 unique keys/elements. That's the base case of {= 1 input, 2 outputs} without address reuse, plus fudged up a bit for multi-s= ends then down a bit again for address reuse.

= 15,000*5=3D75,000 unique elements per block. With an FP rate of 0.1% we get= :


131.63KB per block extra overhead= .

144 blocks in a day, so that's 18mb of d= ata per day's worth of sync to pull down over the network. If you don&#= 39;t start your wallet for a week that's 126 megabytes of data just=C2= =A0to get started.

Affordable, yes (in the west). = Fast enough to be competitive? Doubtful. I don't believe that even in f= ive years mobiles will be pulling down and processing that much data within= a few seconds, not even in developed countries.

B= ut like I said, I don't see why it matters. Anyone who is watching the = wire close to you learns which transactions are yours, still, so it doesn&#= 39;t stop intelligence agencies. Anyone who is running a node learns which = transactions in the requested block were yours and thus can follow the tx c= hain to learn which other transactions might be yours too, no different to = today. If you connect to a single node and say "give me the transactio= ns sending money to key A in block N", it doesn't matter if you th= en don't request block N+6 from the same peer - they know you will requ= est it eventually anyway, just by virtue of the fact that one of the transa= ctions they gave you was spent in that block.


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