From 42ed80e154479b45c8b15809e0781b0e7bea5cd1 Mon Sep 17 00:00:00 2001 From: "David A. Harding" Date: Mon, 6 Jan 2020 06:19:43 -0500 Subject: [PATCH] Newsletters: add 79 (2020-01-08) --- .../en/newsletters/2020-01-08-newsletter.md | 103 ++++++++++++++++++ workshops.md | 7 ++ 2 files changed, 110 insertions(+) create mode 100644 _posts/en/newsletters/2020-01-08-newsletter.md diff --git a/_posts/en/newsletters/2020-01-08-newsletter.md b/_posts/en/newsletters/2020-01-08-newsletter.md new file mode 100644 index 000000000..662fe4a6e --- /dev/null +++ b/_posts/en/newsletters/2020-01-08-newsletter.md @@ -0,0 +1,103 @@ +--- +title: 'Bitcoin Optech Newsletter #79' +permalink: /en/newsletters/2020/01/08/ +name: 2020-01-08-newsletter +slug: 2020-01-08-newsletter +type: newsletter +layout: newsletter +lang: en +--- +This week's newsletter summarizes the final week of the organized +taproot review, describes a discussion about coinjoin mixing without +either equal value inputs or outputs, and mentions a proposal to encode +output script descriptors in end-user interfaces. Also included is our +regular section about notable changes to popular Bitcoin infrastructure +projects. + +{% comment %}{% endcomment %} +{% include references.md %} + +## Action items + +- Bitcoin Optech is planning to hold a third Schnorr and Taproot + seminar workshop in London on February 5th 2020. This will cover + the same material as the previous two [Schnorr/Taproot workshops][], + which is available on this website for home study. + + **Member companies who would like to send engineers to the workshop should + [email Optech][optech email]**. + +## News + +- **Final week of organized taproot review:** December 17th was the + final scheduled [meeting][taproot meeting] of the taproot review + group. Pieter Wuille posted the [slides][wuille slides] from a + presentation he gave summarizing progress, including text indicating + he thought the proposal was "nearly ready". Wuille also proposed a + [minor change][wuille suggestion] to the tapleaf versioning. Also + briefly mentioned was the [discussion][zmn post] started by ZmnSCPxj + on the Lightning-Dev mailing list about how precisely taproot could be + integrated with LN to provide improved privacy and scalability. + +- **Coinjoins without equal value inputs or outputs:** Adam Ficsor + (nopara73) started a [discussion][ficsor non-equal] on the Bitcoin-Dev + mailing list about two previously-published papers ([1][cashfusion], + [2][knapsack]) describing coinjoins that didn't use either equal-value + inputs or outputs. Previous attempts at non-equal mixes were [easy to + compromise][coinjoin sudoku], but if an improved method was found, it + could significantly improve the privacy of coinjoins by making their + transactions look like [payment batching][]. This seemed especially + relevant after reports that a popular exchange was investigating users + participating in the chaumian-style coinjoins created by Wasabi + Wallet. Although several ideas were discussed, we think the [summary][ontivero summary] + by Lucas Ontivero captures the essence of the overall conclusion: "In + summary, unequal inputs/outputs coinjoins [knapsack][] is the best we + have at the moment ([but] it is not as effective as equal-outputs + transactions)." + +- **Encoded descriptors:** Chris Belcher [asked][belcher descriptors] + for feedback from the Bitcoin-Dev mailing list about base64 encoding + [output script descriptors][topic descriptors] so that they're easier + to copy and paste (and also so that regular users aren't exposed to + their code-like syntax). At least one reply was opposed to the idea + and other replies which did support the idea each proposed a different + encoding format. The discussion to date did not come to any + clear conclusion. + +## Notable code and documentation changes + +*Notable changes this week in [Bitcoin Core][bitcoin core repo], +[C-Lightning][c-lightning repo], [Eclair][eclair repo], [LND][lnd repo], +[libsecp256k1][libsecp256k1 repo], [Bitcoin Improvement Proposals +(BIPs)][bips repo], and [Lightning BOLTs][bolts repo].* + +- [C-Lightning #3351][] extends the `invoice` RPC with a new + `exposeprivatechannels` parameter that allows the user to request + the addition of route hints for private channels to a generated [BOLT11][] + invoice. The user may optionally specify which channels they want to + advertise in the invoice, including both public and private channels. + +- [LND #3647][] switches from using base64 to hex for the display of + binary data in the `listinvoices` RPC. This is a breaking API change for users of any + of the updated fields. + +- [LND #3814][] allows the UTXO sweeper to add wallet inputs to a + sweep transaction in order to ensure its output meets the dust limit. + This is designed to help support the proposed anchor outputs feature + (see [Newsletter #70][news70 anchor]) which will need to add inputs to + a transaction in order to be able to spend low-value UTXOs. + +{% include linkers/issues.md issues="3647,3814,3351" %} +[Schnorr/Taproot workshops]: /en/schorr-taproot-workshop/ +[wuille slides]: https://prezi.com/view/AlXd19INd3isgt3SvW8g/ +[wuille suggestion]: http://www.erisian.com.au/meetbot/taproot-bip-review/2019/taproot-bip-review.2019-12-17-19.01.log.html#l-8 +[zmn post]: https://lists.linuxfoundation.org/pipermail/lightning-dev/2019-December/002375.html +[ficsor non-equal]: https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2019-December/017538.html +[cashfusion]: https://github.com/cashshuffle/spec/blob/master/CASHFUSION.md +[knapsack]: https://www.comsys.rwth-aachen.de/fileadmin/papers/2017/2017-maurer-trustcom-coinjoin.pdf +[coinjoin sudoku]: http://www.coinjoinsudoku.com/ +[payment batching]: https://github.com/bitcoinops/scaling-book/blob/master/x.payment_batching/payment_batching.md +[belcher descriptors]: https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2019-December/017529.html +[news70 anchor]: /en/newsletters/2019/10/30/#ln-simplified-commitments +[taproot meeting]: http://www.erisian.com.au/meetbot/taproot-bip-review/2019/taproot-bip-review.2019-12-17-19.01.html +[ontivero summary]: https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2019-December/017544.html diff --git a/workshops.md b/workshops.md index 35fec417b..4ac29f0bb 100644 --- a/workshops.md +++ b/workshops.md @@ -12,6 +12,13 @@ and the specific scaling challenges that they are facing. If you have any requests or suggestions for future workshop events, please [contact us][optech email]. +## Workshop #5 - Schnorr and Taproot Seminars {#taproot-workshop} + +Bitcoin Optech will host a third seminar workshop on the Schnorr and Taproot +soft fork proposals in London on 5th February 2020. + +Member companies who would like to attend should [contact us][optech email]! + ## Workshops #3 & #4 - Schnorr and Taproot Seminars {#taproot-workshop} - San Francisco, September 24 2019