From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 3179C41C for ; Wed, 13 Sep 2017 09:39:30 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-vk0-f46.google.com (mail-vk0-f46.google.com [209.85.213.46]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id AC1F6E0 for ; Wed, 13 Sep 2017 09:39:29 +0000 (UTC) Received: by mail-vk0-f46.google.com with SMTP id t10so15495187vke.0 for ; Wed, 13 Sep 2017 02:39:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:sender:from:date:message-id:subject:to; bh=jZAhLVCRMzXpoM+57+Xdc59GxK3iZ+H9m1+WRwLtbAs=; b=p9Irw9jgN7jY7gxIKIFsOIVHmTEVgiVrmWX3jqDlHbYXeEbEysbIe5uOx82kUL2TKG 4xDfc5iIVQy3X1rCiymXTvTx6ZJ+Jq06Eo4szkZuaVCHK/jlHL6a80Mwhl0VtnlS8+/x 30UYGZwX0EEOudwIFYF4EacpeC5I7iEehVNQDCiatutqVZtvwOH2EMi24oi8RxqaCuJT TguADBhTTKyrRz5pmlxlpEP/OWJevMiYfJ/x8T4SAV8cJvv8kD0Ikq3BF8SOLI1dPRUN BPlDYcj5B+Pugu41iEq0PF/KSpJwuskPF+kPhRkVzEX6wUdxS1OsG7ZxgsTibx3WpAmM o2Dg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:from:date:message-id:subject :to; bh=jZAhLVCRMzXpoM+57+Xdc59GxK3iZ+H9m1+WRwLtbAs=; b=J1PixafCbPUXHdqE/fdQ8faPS1qRwtMNXnOzCHrag3sOssaTe5iAnFvF3WFsavWq5U S/JsEKqtkIALP3qDlr0Je0MgeWbN3sOD5uBjUO9JrEPwUUfr1JtRECq4jh9rxx9xICYH QznmrgUtAqjhHF2dVg6VIfmfKNMIuFG+mL43cQDJs4dQl7bL69O/oDprRTu0PspFAVek VMNpOdoqICzyMdItGsUK/kI2KL8m2O1aY26YxypbdMsP9JAafZFJHsixEVmvYQxHoVFO 28pvq4U0unOtAsuB8AHGIJQOCa9J4Q73PXrt3KmuoVkC3CSsk4UkhQaBuMypwjJz2A6W xuYg== X-Gm-Message-State: AHPjjUicFg9IM2qJC+l+X0eBqqJQOulHpIXGxWpzlaFkdbK+sQ4clseM vCRCLw/ci73FLmCwnUPihC/DGWg0mCFhpRxa9dyCxw== X-Google-Smtp-Source: AOwi7QBRri28ACDPPd5X2dpH3I9nlQZjEieelxJ8ma0LV0O2aRXHKEliiexkq2PH2V3IlPfuB2Mk1lEdaGksTVTjBLo= X-Received: by 10.31.102.133 with SMTP id a127mr6749164vkc.154.1505295568836; Wed, 13 Sep 2017 02:39:28 -0700 (PDT) MIME-Version: 1.0 Sender: gmaxwell@gmail.com Received: by 10.103.146.78 with HTTP; Wed, 13 Sep 2017 02:39:28 -0700 (PDT) From: Gregory Maxwell Date: Wed, 13 Sep 2017 09:39:28 +0000 X-Google-Sender-Auth: OrlPBHMdnGyvONAamgedBEWeXos Message-ID: To: Peter Todd , Bitcoin Protocol Discussion Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=0.0 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, FREEMAIL_FROM,RCVD_IN_DNSWL_NONE autolearn=disabled version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org Subject: [bitcoin-dev] Minutia in CT for Bitcoin. Was: SF proposal: prohibit unspendable outputs with amount=0 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: Wed, 13 Sep 2017 09:39:30 -0000 On Wed, Sep 13, 2017 at 9:24 AM, Peter Todd via bitcoin-dev wrote: > 2) Spending CT-shielded outputs to unshielded outputs > > Here one or more CT-shielded outputs will be spent. Since their value is zero, > we make up the difference by spending one or more outputs from the CT pool, > with the change - if any - assigned to a CT-pool output. Can we solve the problem that pool inputs are gratuitously non-reorg safe, without creating something like a maturity limit for shielded to unshielded? So far the best I have is this: Support unshielded coins in shielded space too. So the only time you transition out of the pool is paying to a legacy wallet. If support were phased in (e.g. addresses that say you can pay me in the pool after its enabled), and the pool only used long after wallets supported getting payments in it, then this would be pretty rare and a maturity limit wouldn't be a big deal. Can better be done?