From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id 87672C016F for ; Mon, 11 May 2020 05:44:16 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by whitealder.osuosl.org (Postfix) with ESMTP id 76CBB875BA for ; Mon, 11 May 2020 05:44:16 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Iq2IP5TrJuoz for ; Mon, 11 May 2020 05:44:13 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail-40138.protonmail.ch (mail-40138.protonmail.ch [185.70.40.138]) by whitealder.osuosl.org (Postfix) with ESMTPS id B4C7F8745D for ; Mon, 11 May 2020 05:44:13 +0000 (UTC) Date: Mon, 11 May 2020 05:44:08 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com; s=protonmail; t=1589175851; bh=aObPBlXHr6WLB1yPmijDlW1WnNV/wdPoNqf9zTXC7e4=; h=Date:To:From:Cc:Reply-To:Subject:In-Reply-To:References:From; b=RM168AGFc/Hqz4T0NGUHfy4pSXN+G9xfpJqijVGP+zVe37f/gGur47iTmHhfWK5FP N6NxKr3chLCivVzzmWptfajdLI3KSqjVXWDDr4N7Tp2FFHSYufuvVxSJIwRXBT7PSU tXNQ3SuWl5ES2cOxtW9Mucz6j8i61ohXEmJRRBxw= To: Richard Myers From: ZmnSCPxj Reply-To: ZmnSCPxj Message-ID: In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: Bitcoin Protocol Discussion , "lightning-dev\\\\\\\\@lists.linuxfoundation.org" Subject: Re: [bitcoin-dev] [Lightning-dev] On the scalability issues of onboarding millions of LN mobile clients X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Bitcoin Protocol Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 11 May 2020 05:44:16 -0000 Good morning Richard, and all, > 2) a=C2=A0light client can query an ISP connected full node on the same u= nmetered local WiFi network and exchange differences in block headers oppor= tunistically or pay for large missing ranges of headers, filters or full bl= ocks using a payment channel. Cost is reduced and privacy=C2=A0is enhanced = for the light client by not using a centralized ISP. Bandwidth for running = the full node can be amortized=C2=A0and subsidized by payments from light c= lients who they resell data to. A relatively pointless observation, but it seems to me that: * The light client is requesting for validation information, because... * ...its direct peers might be defrauding it, leading to... * ...the money it *thinks* it has in its channels being valueless. Thus, if the light client opportunistically pays for validation information= (whether full blocks, headers, or filters), the direct peers it has could = just as easily not forward any payments, thus preventing the light client f= rom paying for the validation information. Indeed, if the direct peer *is* defrauding the light client, the direct pee= r has no real incentive to actually forward *any* payments --- to do so wou= ld be to reduce the possible earnings it gets from defrauding the light cli= ent. ("Simulating" the payments so that the light client will not suspect anythi= ng runs the risk that the light client will be able to forward all its mone= y out of the channel, and the cheating peer is still potentially liable for= any funds it originally had in the channel if it gets caught.) What would work would be to use a system similar to watchtowers, wherein th= e validation-information-provider is prepaid and issues tokens that can be = redeemed later. But this is not suitable for opportunistic on-same-WiFi where, say, a lapto= p is running a validation-information-provider-for-payment program on the s= ame WiFi as a light-client mobile phone, if we consider that the laptop and= mobile may have never met before and may never meet again. It would work if the laptop altruistically serves the blocks, but not if it= were for (on-Lightning) payment. So it seems to me that this kind of service is best ridden on top of watcht= ower service providers. Regards, ZmnSCPxj