Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id BE4BAB7B for ; Sat, 1 Apr 2017 23:49:07 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from cock.li (cock.li [185.100.85.212]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id C93C7FD for ; Sat, 1 Apr 2017 23:49:06 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org X-Spam-Level: X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU autolearn=ham version=3.3.1 MIME-Version: 1.0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cock.lu; s=mail; t=1491090543; bh=0AgZcQVvGwsLYtr2b2Nlpd11UMOR5vZubQRkHk74qM8=; h=Date:From:To:Subject:In-Reply-To:References:From; b=hRwmrFI+7npi7YXm8yLF/mGMhbyZsvpZd/gv6iYUAp7M68IexfR3gVtr8RYaGR7bZ Mi9A0nsh2CCHAl+5hNg59i1VJWLtSOaZSk2YkZcGP49ehbBv1llji0LrmgVaEC9sEn HnAzPHHiIHhfN92pIxSjrCh9EVro343laTfdWR7paN4GpOv2bgyoEBgP7rVYO03THr kKfaOwWK4dE6hzS2pfvX1+3CWFbvrTMnZ2SnOxrNtT3ohI/U3UCGnNF27lbjRq0Etx LYM/sxkOCKeiANtWuaosIb0L95w6j7iGPj0ifJCJ+MpLy4qY7qS6U7Fr0c3mTWhBF7 aCKa1aT/HZENg== Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Sun, 02 Apr 2017 09:49:03 +1000 From: bfd@cock.lu To: Chris Belcher , Bitcoin Protocol Discussion In-Reply-To: References: <71d822e413ac457a530e1c367811cc24@cock.lu> Message-ID: X-Sender: bfd@cock.lu User-Agent: Roundcube Webmail/1.2.3 X-Mailman-Approved-At: Sat, 01 Apr 2017 23:50:17 +0000 Subject: Re: [bitcoin-dev] Committed bloom filters for improved wallet performance and SPV security 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: Sat, 01 Apr 2017 23:49:07 -0000 On 2017-02-17 11:28, Chris Belcher via bitcoin-dev wrote: > I think this committed bloom filter idea is very good and much better > than bip37, but for good privacy for when bitcoin is used often still > requires certain behavior namely downloading blocks > from many different peers with new tor circuits. > > Note that I've been dealing with counting transaction subgraphs but > actually finding them from blocks might also be computationally > infeasible. Although a Bayesian approach worked very > well for similar transaction subgraph linking > [https://arxiv.org/pdf/1612.06747v3.pdf] > > It would also be interesting to analyze what information a spy can get > if they are missing some blocks that the wallet downloaded. > > For the long term, private and high-volume bitcoin use will be best > served by off-chain transactions. They will probably be a huge win just > because the large and public blockchain is such a non-private > way of doing things. > Thank you for the analysis, this generally matches my views about the properties offered by the system. I've generally developed the opinion that BIP37 is effectively unused by all but a very small number of wallets and services now, setting up sinkhole nodes in the network to monitor `filterload` commands seems to back that up.