Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1XEjsU-0005Gt-0i for bitcoin-development@lists.sourceforge.net; Tue, 05 Aug 2014 18:54:30 +0000 Received-SPF: pass (sog-mx-3.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.219.44 as permitted sender) client-ip=209.85.219.44; envelope-from=mh.in.england@gmail.com; helo=mail-oa0-f44.google.com; Received: from mail-oa0-f44.google.com ([209.85.219.44]) by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1XEjsE-0001HA-PD for bitcoin-development@lists.sourceforge.net; Tue, 05 Aug 2014 18:54:29 +0000 Received: by mail-oa0-f44.google.com with SMTP id eb12so1021411oac.17 for ; Tue, 05 Aug 2014 11:54:09 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.60.103.50 with SMTP id ft18mr8535594oeb.47.1407264848848; Tue, 05 Aug 2014 11:54:08 -0700 (PDT) Sender: mh.in.england@gmail.com Received: by 10.76.35.234 with HTTP; Tue, 5 Aug 2014 11:54:08 -0700 (PDT) In-Reply-To: References: Date: Tue, 5 Aug 2014 20:54:08 +0200 X-Google-Sender-Auth: ovuX4Hh0doC347ZLW5QjJfJqRFQ Message-ID: From: Mike Hearn To: Jeff Garzik Content-Type: multipart/alternative; boundary=089e011606026bacee04ffe661c4 X-Spam-Score: -0.5 (/) 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 (mh.in.england[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 1.0 HTML_MESSAGE BODY: HTML included in message 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 0.0 TIME_LIMIT_EXCEEDED Exceeded time limit / deadline X-Headers-End: 1XEjsE-0001HA-PD Cc: Bitcoin Dev Subject: Re: [Bitcoin-development] deterministic transaction expiration 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: Tue, 05 Aug 2014 18:54:30 -0000 --089e011606026bacee04ffe661c4 Content-Type: text/plain; charset=UTF-8 > > The user experience of unconfirming transactions setting around in limbo > is just horrible. Bitcoin software by necessity has gotten better about > attaching fees so this sort of behavior is uncommon, but that does not > eliminate the problem. > Yes, indeed. I suspect there's a quick hack that could make this problem a lot better though. I think I brought up this idea before, but can't quite remember. Anyway I'm willing to bet that if we analysed the data some more, we'd discover that most "legitimate" i.e. non-DoS unconfirmed transactions that sit around for ages are linked back to the block chain within two hops and not more. That is people send a transaction that uses up their coin age, and then immediately those coins are immediately respent again, but then those final new coins are not spent. On the other hand DoS attacks look like bouncing your coins around over and over forever, i.e. more than two or three hops back to the chain. So I wonder if making priority look back two or three transactions but not more would help real users a lot, whilst not opening up any significant new potential for DoS. --089e011606026bacee04ffe661c4 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
The user experie= nce of unconfirming transactions setting around in limbo is just horrible.= =C2=A0 Bitcoin software by necessity has gotten better about attaching fees= so this sort of behavior is uncommon, but that does not eliminate the prob= lem.

Yes, indeed. I sus= pect there's a quick hack that could make this problem a lot better tho= ugh.

I think I brought up this idea before, but ca= n't quite remember. Anyway I'm willing to bet that if we analysed t= he data some more, we'd discover that most "legitimate" i.e. = non-DoS unconfirmed transactions that sit around for ages are linked back t= o the block chain within two hops and not more. That is people send a trans= action that uses up their coin age, and then immediately those coins are im= mediately respent again, but then those final new coins are not spent.

On the other hand DoS attacks look like bouncing your c= oins around over and over forever, i.e. more than two or three hops back to= the chain.

So I wonder if making priority look ba= ck two or three transactions but not more would help real users a lot, whil= st not opening up any significant new potential for DoS.=C2=A0
--089e011606026bacee04ffe661c4--