Improve description of note components.

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

protocol/protocol.tex

@@ -1247,15 +1247,21 @@ and set bit $6$ of the last byte.'' Here the bits of a byte are numbered
 such that bit $b$ has numeric weight $2^b$.
 \end{itemize}
 }
-
 \nsubsection{Note Components}
 
+A \note consists of $(\AuthPublic, \Value, \NoteAddressRand, \NoteCommitRand)$ where
 \begin{itemize}
-    \item $\AuthPublic$ is a 32-byte \payingKey of the recipient.
-    \item $\Value$ is a 64-bit unsigned integer representing the value of the
-        \note in \zatoshi ($1$ \ZEC = $10^8$ \zatoshi).
-    \item $\NoteAddressRand$ is a 32-byte $\PRFnf{\AuthPrivate}$ preimage.
-    \item $\NoteCommitRand$ is a 32-byte \commitmentTrapdoor.
+  \item $\AuthPublic \typecolon \PRFOutput$ is the
+        \payingKey of the recipient;
+  \item $\Value \typecolon \range{0}{\MAXMONEY}$ is an integer
+        representing the value of the \note in \zatoshi
+        ($1$ \ZEC = $10^8$ \zatoshi);
+  \item $\NoteAddressRand \typecolon \PRFOutput$
+        is used as input to $\PRFnf{\AuthPrivate}$ to derive the
+        \nullifier of the \note;
+  \item $\NoteCommitRand \typecolon \bitseq{\NoteCommitRandLength}$
+        is a random bit sequence used as a \commitmentTrapdoor as
+        defined in \crossref{abstractcomm}.
 \end{itemize}
 
 \nsubsection{\JoinSplitDescriptions} \label{joinsplitdesc}