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 E5F32D56 for ; Wed, 17 Jul 2019 07:52:58 +0000 (UTC) X-Greylist: delayed 00:08:30 by SQLgrey-1.7.6 Received: from mo.garage.hdemail.jp (mo.garage.hdemail.jp [46.51.242.127]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 895D6879 for ; Wed, 17 Jul 2019 07:52:57 +0000 (UTC) Received: from ip-10-217-1-36.ap-northeast-1.compute.internal (localhost.localdomain [127.0.0.1]) by mo.garage.hdemail.jp (hde-mf-postfix) with SMTP id 558FC14C100 for ; Wed, 17 Jul 2019 16:44:26 +0900 (JST) (envelope-from karljohan-alm@garage.co.jp) X-Received: from unknown (HELO mo.garage.hdemail.jp) (127.0.0.1) by 0 with SMTP; 17 Jul 2019 16:44:26 +0900 X-Received: from mo.garage.hdemail.jp (localhost.localdomain [127.0.0.1]) by mo.garage.hdemail.jp (hde-ma-postfix) with ESMTP id 4D1C94C096 for ; Wed, 17 Jul 2019 16:44:26 +0900 (JST) (envelope-from karljohan-alm@garage.co.jp) Received: from gw31.oz.hdemail.jp (ip-10-122-153-121.ap-northeast-1.compute.internal [10.122.153.121]) by mo.garage.hdemail.jp (hde-mf-postfix) with ESMTP id 4723814C100 for ; Wed, 17 Jul 2019 16:44:26 +0900 (JST) (envelope-from karljohan-alm@garage.co.jp) X-Received: from mail-qt1-f197.google.com (lb05.oz.hdemail.jp [54.238.57.175]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by gw31.oz.hdemail.jp (Postfix) with ESMTP id D8CEF148C130 for ; Wed, 17 Jul 2019 16:44:25 +0900 (JST) X-Received: by mail-qt1-f197.google.com with SMTP id y19so20534449qtm.0 for ; Wed, 17 Jul 2019 00:44:25 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=WifUYb410G/3Jfg0SfkYvDLxybZL21+Wr7l1qRSLbYg=; b=k5W0+Z1KrPZpitenOVv33lt5LSCLJIJSIYnEyjS/r9hRA7jLvlxLw7c65YBAia4z9K Lp1q04ui9SQXasaz4APj/uLGQ1ShUD9avEHzIvGnDOntR+rfyk+KMvL6uMFGTOgeRwoU kug7jXW8+6V8mAFiCFmiJUskYtw4cefxEwIOLzv0R2+HQoQthxfb9tZKKVEkeGaK3y4+ t1HXJ97vDIXRHeaJL2KAgBKgRpyK5X8pBTmLWbCp3k+6IQf0daQe5CML6SYxAPUakd0c mb9EKIo0czb6eiLo4J4zbbPSeOVcjFdCI8cpNkrgJfFuEDc77ZecbTbK6Po85sMLigHR 9GJA== X-Gm-Message-State: APjAAAWFRbqiNAf3CHMg+HYlwoEIVHji5oIHltJYN63y8aoj+9lXmQi3 KUh8iXY8IvfedZJLbnmh/yIya7DDEwBF+WsfiYKLkOGnsim7nSMyT1crItcdvJPc7sQe9Z2zTED tWDM9qWGdole0I2qXj5PlhrIBNC06icseHLjYppgAvaGaeIWC3avD7PLnmvatcTGAYQG5cVRVsN fyJS8Npi5XVxIq1Xi/0fZlKRhCrfdNfafr4C4o7IJkohJfpq4ozJenLQqvJY2R5G1qDIAPuuGNs RxWj0ZLuWFSz/WozFP54QkXb6KNmUXuW31ZIlV5N2ZdjooXU4zRHKI2ZB370D+trN7+ay8crYow Rz6BY7AKrhRnq+7fshdiAZMY/Oc= X-Received: by 2002:a05:6214:1c3:: with SMTP id c3mr21215222qvt.144.1563349464431; Wed, 17 Jul 2019 00:44:24 -0700 (PDT) X-Google-Smtp-Source: APXvYqxLII+TzCR+S+vstnuOdZp5QNrbnghpcT0acdCINTBze9pbqRenNXTjfrHymzjiqcCVxEKeyqtf8M3JV0toql0= X-Received: by 2002:a05:6214:1c3:: with SMTP id c3mr21215202qvt.144.1563349464014; Wed, 17 Jul 2019 00:44:24 -0700 (PDT) MIME-Version: 1.0 From: Karl-Johan Alm Date: Wed, 17 Jul 2019 16:44:13 +0900 Message-ID: To: Bitcoin Protocol Discussion Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org X-Mailman-Approved-At: Wed, 17 Jul 2019 08:08:28 +0000 Subject: [bitcoin-dev] BIP: Signet 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, 17 Jul 2019 07:52:59 -0000 Hello, I have written a BIP describing the Signet network. Feedback requested! https://github.com/bitcoin/bips/pull/803 Pasted in its entirety below, with formatting issues left as is. See above link for styled version. 
BIP: XXXX
Layer: Applications
Title: Signet
Author: Karl-Johan Alm 
Comments-Summary: No comments yet.
Comments-URI: https://github.com/bitcoin/bips/wiki/Comments:BIP-XXXX
Status: Draft
Type: Standards Track
Created: 2019-03-20
License: CC0-1.0
== Abstract == A new type of test network where signatures are used in addition to proof of work for block progress, enabling much better coordination and robustness (be reliably unreliable), for persistent, longer-term testing scenarios involving multiple independent parties. == Motivation == Testnet is a great place to try out new things without risking real money, but it is notoriously unreliable. Huge block reorgs, long gaps in between blocks being mined or sudden bursts of blocks in rapid succession mean that realistic testing of software, especially involving multiple independent parties running software over an extended period of time, becomes infeasible in practice. A new type of test network would be more suitable for integration testing by organizations such as exchanges, or testing of next generation Layer-2 protocols like Eltoo or sidechain pegs. The goal is not to be perfectly reliable but rather to have a predictable amount of unreliability. You want a test network to behave like mainnet (i.e. no thousands of block reorgs) while also making it easier to trigger expected but rare events like a 6-block reorg. Regtest is not suitable for longer-term scenarios involving multiple independent parties because creating blocks costs nothing, so any party can completely control the test network. == Specification == A new type of network ("signet"), which takes an additional consensus parameter called the challenge (scriptPubKey). The challenge can be a simple pubkey (P2PKH style), or a k-of-n multisig, or any other script you would want. The witness commitment of the coinbase transaction is extended to include a secondary commitment (the signature/solution): 1-4 bytes - Push the following (x + 4) bytes 4 bytes - Signet header (0xecc7daa2) x bytes - Solution (sigScript) Any push operations that do not start with the 4 byte signet header are ignored. Multiple push operations with the 4 byte signet header are ignored except for the first entry. Any signature operations contained within the challenge use SHA256d(modifiedBlockHash), i.e. the double-SHA256 digest of the following data as the sighash: {|class="wikitable" style="text-align: center;" |- !Type !Size !Name |- |Int32||4||nVersion |- |Uint256||32||hashPrevBlock |- |Uint256||32||modifiedMerkleRoot |- |Uint32||4||nTime |- |Uint32||4||nBits |} The modifiedMerkleRoot hash is obtained by generating the merkle root of the block transactions, with the coinbase witness commitment as is, without the signet extension. This means the merkle root of the block is different from the merkle root in the signet commitment, but in return, the block nonce value is the only component that the signet signature does not commit to. When grinding proof of work, the extended nonce cannot be used as it would invalidate the signature. Instead, simply resigning the same (or an updated) block will give a new search space. A block is considered fully validated if the above commitment is found, and its solution is valid. This verification should be done directly before or after the witness commitment verification. == Compatibility == This specification is backwards compatible in the sense that existing software can use Signet out of the box. Simply by adding the network parameters for signet (magic number, etc), a client can connect to and use any signet network without further modifications. The block headers have valid proof of work, so clients can trivially check that blocks are "probably" valid. However, anyone can mine blocks that are accepted by the client for any given signet network. These blocks do not contain the required signatures, however, so any fully validating node will promptly reject them. As such, clients need to either validate the block signature inside the coinbase transaction, or connect to trusted peers. Other software need not add block signature validation code that they will not use in production. This is adequate for non-production test purposes where the goal is to have a network behave as much like mainnet as possible. == Reference implementation == WIP implementation at https://github.com/kallewoof/bitcoin/pull/4 == Acknowledgements == TODO == References == # Original mailing list thread: https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2019-March/016734.html # Bitcoin Wiki entry: https://en.bitcoin.it/wiki/Signet == Copyright == This document is licensed under the Creative Commons CC0 1.0 Universal license.