Newsletters: add 402 (2026-04-24)

_posts/en/newsletters/2026-04-24-newsletter.md

@@ -0,0 +1,71 @@
+---
+title: 'Bitcoin Optech Newsletter #402'
+permalink: /en/newsletters/2026/04/24/
+name: 2026-04-24-newsletter
+slug: 2026-04-24-newsletter
+type: newsletter
+layout: newsletter
+lang: en
+---
+FIXME:bitschmidty
+
+## News
+
+FIXME:bitschmidty
+
+## Selected Q&A from Bitcoin Stack Exchange
+
+*[Bitcoin Stack Exchange][bitcoin.se] is one of the first places Optech
+contributors look for answers to their questions---or when we have a
+few spare moments to help curious or confused users.  In
+this monthly feature, we highlight some of the top-voted questions and
+answers posted since our last update.*
+
+{% comment %}<!-- https://bitcoin.stackexchange.com/search?tab=votes&q=created%3a1m..%20is%3aanswer -->{% endcomment %}
+{% assign bse = "https://bitcoin.stackexchange.com/a/" %}
+
+- [Why did BIP342 replace CHECKMULTISIG with a new opcode, instead of just removing FindAndDelete from it?]({{bse}}130665)
+  Pieter Wuille explains that the replacement of `OP_CHECKMULTISIG` with
+  `OP_CHECKSIGADD` in [tapscript][topic tapscript] was necessary to enable batch
+  verification of [schnorr][topic schnorr signatures] signatures (see
+  [Newsletter #46][news46 batch]) in a potential future protocol change.
+
+- [Does SIGHASH_ANYPREVOUT commit to the tapleaf hash or the full taproot merkle path?]({{bse}}130637)
+  Antoine Poinsot confirms that [SIGHASH_ANYPREVOUT][topic sighash_anyprevout]
+  signatures currently commit only to the tapleaf hash, not the full merkle path
+  in the [taproot][topic taproot] tree. However, this design is under discussion
+  as one BIP co-author has suggested committing to the full merkle path instead.
+
+- [What does the BIP86 tweak guarantee in a MuSig2 Lightning channel, beyond address format?]({{bse}}130652)
+  Ava Chow points out that the tweak prevents the use of hidden script paths
+  because [MuSig2's][topic musig] signing protocol requires all participants to
+  apply the same [BIP86][] tweak for signature aggregation to succeed. If one
+  party attempts to use a different tweak, such as one derived from a hidden
+  script tree, their partial signature won't aggregate into a valid final
+  signature.
+
+## Releases and release candidates
+
+_New releases and release candidates for popular Bitcoin infrastructure
+projects.  Please consider upgrading to new releases or helping to test
+release candidates._
+
+FIXME:Gustavojfe
+
+## Notable code and documentation changes
+
+_Notable recent changes in [Bitcoin Core][bitcoin core repo], [Core
+Lightning][core lightning repo], [Eclair][eclair repo], [LDK][ldk repo],
+[LND][lnd repo], [libsecp256k1][libsecp256k1 repo], [Hardware Wallet
+Interface (HWI)][hwi repo], [Rust Bitcoin][rust bitcoin repo], [BTCPay
+Server][btcpay server repo], [BDK][bdk repo], [Bitcoin Improvement
+Proposals (BIPs)][bips repo], [Lightning BOLTs][bolts repo],
+[Lightning BLIPs][blips repo], [Bitcoin Inquisition][bitcoin inquisition
+repo], and [BINANAs][binana repo]._
+
+FIXME:Gustavojfe
+
+{% include snippets/recap-ad.md when="2026-04-28 16:30" %}
+{% include references.md %}
+{% include linkers/issues.md v=2 issues="" %}
+[news46 batch]: /en/newsletters/2019/05/14/#new-script-based-multisig-semantics