Protected -> shielded.

Signed-off-by: Daira Hopwood <daira@jacaranda.org>

protocol/protocol.tex

@@ -127,6 +127,7 @@
 \newcommand{\term}[1]{\textsl{#1}\kern 0.05em\xspace}
 \newcommand{\titleterm}[1]{#1}
 \newcommand{\termbf}[1]{\textbf{#1}\xspace}
+\newcommand{\quotedterm}[1]{``~\!\!\term{#1}''}
 \newcommand{\conformance}[1]{\textbnx{#1}\xspace}
 
 \newcommand{\Zcash}{\termbf{Zcash}}
@@ -222,11 +223,11 @@
 \newcommand{\xTransparent}{\term{Transparent}}
 \newcommand{\Transparent}{\titleterm{Transparent}}
 \newcommand{\transparentValuePool}{\term{transparent value pool}}
-\newcommand{\xprotected}{\term{protected}}
-\newcommand{\protectedNote}{\term{protected note}}
-\newcommand{\protectedNotes}{\term{protected notes}}
-\newcommand{\xProtected}{\term{Protected}}
-\newcommand{\Protected}{\titleterm{Protected}}
+\newcommand{\shielded}{\term{shielded}}
+\newcommand{\shieldedNote}{\term{shielded note}}
+\newcommand{\shieldedNotes}{\term{shielded notes}}
+\newcommand{\xShielded}{\term{Shielded}}
+\newcommand{\Shielded}{\titleterm{Shielded}}
 \newcommand{\blockchainview}{\term{block chain view}}
 \newcommand{\blockchain}{\term{block chain}}
 \newcommand{\mempool}{\term{mempool}}
@@ -651,7 +652,7 @@
 scheme \Zerocash \cite{BCG+2014}, with some security fixes and adjustments
 to terminology, functionality and performance. It bridges the existing
 \emph{transparent} payment scheme used by \Bitcoin \cite{Naka2008} with a
-\emph{protected} payment scheme secured by zero-knowledge succinct
+\emph{shielded} payment scheme secured by zero-knowledge succinct
 non-interactive arguments of knowledge (\zkSNARKs).
 
 Changes from the original \Zerocash are explained in \crossref{differences},
@@ -706,9 +707,9 @@ behind the protocol, for an audience already familiar with \blockchain-based
 cryptocurrencies such as \Bitcoin. It is imprecise in some aspects and is not
 part of the normative protocol specification.
 
-Value in \Zcash is either \transparent or \xprotected. Transfers of \transparent
+Value in \Zcash is either \transparent or \shielded. Transfers of \transparent
 value work essentially as in \Bitcoin and have the same privacy properties.
-\xProtected value is carried by \notes\hairspace\footnote{\label{notesandnullifiers}
+\xShielded value is carried by \notes\hairspace\footnote{\label{notesandnullifiers}
 In \Zerocash \cite{BCG+2014}, \notes were called ``coins'', and \nullifiers
 were called ``serial numbers''.},
 which specify an amount and a \payingKey. The \payingKey is part of
@@ -1032,7 +1033,7 @@ views of valid \blocks, and therefore of the sequence of \treestates in those
 \nsubsection{\JoinSplitTransfers{} and Descriptions} \label{joinsplit}
 
 A \joinSplitDescription is data included in a \transaction that describes a \joinSplitTransfer,
-i.e.\ a \xprotected value transfer. This kind of value transfer is the primary
+i.e.\ a \shielded value transfer. This kind of value transfer is the primary
 \Zcash-specific operation performed by \transactions; it uses, but should not be
 confused with, the \joinSplitStatement used for the \zkSNARK proof and verification.
 
@@ -1479,7 +1480,7 @@ $\hSigCRH$ is instantiated in \crossref{hsigcrh}.
 
 \nsubsection{Sending \Notes} \label{send}
 
-In order to send \xprotected value, the sender constructs a \transaction
+In order to send \shielded value, the sender constructs a \transaction
 containing one or more \joinSplitDescriptions. This involves first generating
 a new $\JoinSplitSig$ key pair:
 
@@ -2461,7 +2462,7 @@ The raw encoding of a P2PKH address consists of:
 These are encoded in the same way as in \Bitcoin \cite{Bitcoin-Base58},
 for both the production and test networks.
 
-\nsubsubsection{\Protected{} Payment Addresses} \label{paymentaddrencoding}
+\nsubsubsection{\Shielded{} Payment Addresses} \label{paymentaddrencoding}
 
 A \paymentAddress consists of $\AuthPublic$ and $\TransmitPublic$.
 $\AuthPublic$ is a $\SHAName$ output.
@@ -3237,13 +3238,13 @@ In \Zcash, there is only the original \Bitcoin transaction type,
 which is extended to contain a sequence of zero or more
 \Zcash-specific operations.
 
-This allows for the possibility of chaining transfers of \xprotected
-value in a single \Zcash \transaction, e.g.\ to spend a \protectedNote
+This allows for the possibility of chaining transfers of \shielded
+value in a single \Zcash \transaction, e.g.\ to spend a \shieldedNote
 that has just been created. (In \Zcash, we refer to value stored in
 UTXOs as \transparent, and value stored in \joinSplitTransfer output
-\notes as \xprotected.)
+\notes as \shielded.)
 This was not possible in the \Zerocash design without using multiple
-transactions. It also allows \transparent and \xprotected transfers to
+transactions. It also allows \transparent and \shielded transfers to
 happen atomically --- possibly under the control of nontrivial script
 conditions, at some cost in distinguishability.
 
@@ -3260,12 +3261,12 @@ more detail in \crossref{notept}.
 \nsubsection{Unification of Mints and Pours}
 
 In the original \Zerocash protocol, there were two kinds of transaction
-relating to \protectedNotes:
+relating to \shieldedNotes:
 \begin{itemize}
   \item a ``Mint'' transaction takes value from \transparent UTXOs as
-input and produces a new \protectedNote as output.
-  \item a ``Pour'' transaction takes up to $\NOld$ \protectedNotes
-as input, and produces up to $\NNew$ \protectedNotes and a
+input and produces a new \shieldedNote as output.
+  \item a ``Pour'' transaction takes up to $\NOld$ \shieldedNotes
+as input, and produces up to $\NNew$ \shieldedNotes and a
 \transparent UTXO as output.
 \end{itemize}
 
@@ -3287,7 +3288,7 @@ described below, since no special case is needed for Mints.
 
 \nsubsection{Faerie Gold attack and fix} \label{faeriegold}
 
-When a \protectedNote is created in \Zerocash, the creator is
+When a \shieldedNote is created in \Zerocash, the creator is
 supposed to choose a new $\NoteAddressRand$ value at random.
 The \nullifier of the \note is derived from its \spendingKey
 ($\AuthPrivate$) and $\NoteAddressRand$. The \noteCommitment
@@ -3647,6 +3648,12 @@ The errors in the proof of Ledger Indistinguishability mentioned in
 
 \nsection{Change history}
 
+\subparagraph{2016.0-beta-1.9}
+
+\begin{itemize}
+    \item Change \quotedterm{protected} terminology to \quotedterm{shielded}.
+\end{itemize}
+
 \subparagraph{2016.0-beta-1.8}
 
 \begin{itemize}