From ecba2451bc5ef607de208820666399067837f552 Mon Sep 17 00:00:00 2001
From: Daira Hopwood <daira@jacaranda.org>
Date: Fri, 23 Apr 2021 22:05:21 +0100
Subject: [PATCH] Include the diversifier key in an encoded Orchard Incoming
 Viewing Key.

Signed-off-by: Daira Hopwood <daira@jacaranda.org>
---
 protocol/protocol.tex | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/protocol/protocol.tex b/protocol/protocol.tex
index eccc71f9..ef5fcc6f 100644
--- a/protocol/protocol.tex
+++ b/protocol/protocol.tex
@@ -11792,8 +11792,8 @@ instead use a \unifiedPaymentAddress as defined in \crossref{unifiedpaymentaddre
 \vspace{-1ex}
 Let $\KA{Orchard}$ be as defined in \crossref{concreteorchardkeyagreement}.
 
-An \Orchard{} \defining{\incomingViewingKey} consists of a $\KAPrivate{Orchard}$ key
-$\InViewingKey$, restricted to the range $\InViewingKeyTypeOrchard$.
+An \Orchard{} \defining{\incomingViewingKey} consists of a \diversifierKey $\DiversifierKey$,
+and a $\KAPrivate{Orchard}$ key $\InViewingKey$ restricted to the range $\InViewingKeyTypeOrchard$.
 It is derived as described in \crossref{orchardkeycomponents}, and is used with the
 encryption scheme defined in \crossref{saplingandorchardinband}.
 
@@ -11805,12 +11805,14 @@ The \rawEncoding of an \Orchard \incomingViewingKey consists of:
 \vspace{0.5ex}
 \begin{equation*}
 \begin{bytefield}[bitwidth=0.07em]{256}
+    \sbitbox{256}{$\DiversifierKey$}
     \sbitbox{256}{$\ItoLEOSPOf{256}{\InViewingKey}$}
 \end{bytefield}
 \end{equation*}
 
 \vspace{-1.5ex}
 \begin{itemize}
+  \item $32$ bytes specifying $\DiversifierKey$.
   \item $32$ bytes (little-endian) specifying $\InViewingKey$.
 \end{itemize}
 
@@ -14232,6 +14234,7 @@ Peter Newell's illustration of the Jubjub bird, from \cite{Carroll1902}.
 \nufive{
     \item Add the \nConsensusBranchId{} field to v5 \transactions, matching the \consensusBranchID
           used for \sighashTxHashes.
+    \item Include the \diversifierKey in an encoded \Orchard Incoming Viewing Key.
 } %nufive
     \item Explicitly say that \coinbaseTransactions \MUSTNOT have \transparentInputs
           (this is a consensus rule inherited from \Bitcoin which has been present since launch).