From a4d9938ed23039538c9f94f5f9e4805e6b196d44 Mon Sep 17 00:00:00 2001
From: Salvatore Ingala <6681844+bigspider@users.noreply.github.com>
Date: Fri, 8 Nov 2024 12:46:16 +0000
Subject: [PATCH] Explicitly forbid repeated key indexes in musig()

---
 bip-0388.mediawiki | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/bip-0388.mediawiki b/bip-0388.mediawiki
index 0ee4ac9a..19091cfb 100644
--- a/bip-0388.mediawiki
+++ b/bip-0388.mediawiki
@@ -198,6 +198,8 @@ The public keys obtained by deserializing elements of the key information vector
 
 If two <tt>KEY</tt> are <tt>KP/<M;N>/*</tt> and <tt>KP/<P;Q>/*</tt> for the same key placeholder <tt>KP</tt>, then the sets <tt>{M, N}</tt> and <tt>{P, Q}</tt> must be disjoint. Two <tt>musig</tt> key placeholders are the same if they have exactly the same set of key indexes (regardless of the order).
 
+Repeated <tt>KI</tt> expressions are not allowed inside a <tt>musig</tt> placeholder.
+
 The key information vector should be ordered so that placeholder <tt>@i</tt> never appears for the first time before an occurrence of <tt>@j</tt>  for some <tt>j < i</tt>; for example, the first placeholder is always <tt>@0</tt>, the next one is <tt>@1</tt>, etc.
 
 === Descriptor derivation ===