From bde776ecb8afc18e0f320d53c6f516105a18d6e8 Mon Sep 17 00:00:00 2001
From: Sjors Provoost <sjors@sprovoost.nl>
Date: Tue, 22 Sep 2026 14:52:10 +0200
Subject: [PATCH] bip138: collect and deduplicate recipient keys across the
 backup

---
 bip-0138.md                               |  3 ++-
 bip-0138/test_vectors/recipient_keys.json | 12 ++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/bip-0138.md b/bip-0138.md
index f1f2a268..e44571c3 100644
--- a/bip-0138.md
+++ b/bip-0138.md
@@ -98,7 +98,8 @@ Note: in the following sections, the operator ⊕ refers to the bitwise XOR oper
 
 ### Secret generation
 
-- Let $p_1, p_2, \dots, p_n$, be the public keys in the descriptor/wallet policy, in
+- Let $p_1, p_2, \dots, p_n$, be the distinct public keys across all descriptor
+  and policy sets and all content items in the payload, in
   increasing lexicographical order. The scheme is defined for any $n \geq 1$,
   in particular it supports single-signature descriptors ($n = 1$). Each $p_i$
   is the x-only-normalized root public key of one *allowed* key expression
diff --git a/bip-0138/test_vectors/recipient_keys.json b/bip-0138/test_vectors/recipient_keys.json
index 05f4c8f0..5105a7e7 100644
--- a/bip-0138/test_vectors/recipient_keys.json
+++ b/bip-0138/test_vectors/recipient_keys.json
@@ -91,5 +91,17 @@
       "8b42cd4776376c82791b494155151f56c2d7b471e0c7a526a7ce60dd872e3867",
       "ebd252ca0877aae09b9d058219682775aa3cbcd049c12f07832f2cf6a3b51708"
     ]
+  },
+  {
+    "description": "Same root in several descriptor sets contributes once",
+    "descriptors": [
+      "tr(tpubDEPBvXvhta3pjVaKokqC3eeMQnszj9ehFaA2zD5nSdkaccwGAizu8jVB2NeSpvmP2P52MBoZvNCixqXRJnTyXx51FQzARR63tjxQSyP3Btw/0/*)",
+      "tr(tpubDEPBvXvhta3pjVaKokqC3eeMQnszj9ehFaA2zD5nSdkaccwGAizu8jVB2NeSpvmP2P52MBoZvNCixqXRJnTyXx51FQzARR63tjxQSyP3Btw/1/*)",
+      "tr(tpubDC5FSnBiZDMmhiuCmWAYsLwgLYrrT9rAqvTySfuCCrgsWz8wxMXUS9Tb9iVMvcRbvFcAHGkMD5Kx8koh4GquNGNTfohfk7pgjhaPCdXpoba/*)"
+    ],
+    "expected_keys": [
+      "8b42cd4776376c82791b494155151f56c2d7b471e0c7a526a7ce60dd872e3867",
+      "ebd252ca0877aae09b9d058219682775aa3cbcd049c12f07832f2cf6a3b51708"
+    ]
   }
 ]