Updates to random seed.

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

protocol/protocol.tex

@@ -386,6 +386,8 @@
 \newcommand{\EdDSAs}{S}
 \newcommand{\EdDSAR}{\bytes{R}}
 \newcommand{\EdDSAS}{\bytes{S}}
+\newcommand{\RandomSeedLength}{\mathsf{\ell_{Seed}}}
+\newcommand{\RandomSeedType}{\bitseq{\mathsf{\ell_{Seed}}}}
 
 % Merkle tree
 \newcommand{\MerkleDepth}{\mathsf{d}}
@@ -411,6 +413,7 @@
 \newcommand{\commitments}{\mathtt{commitments}}
 \newcommand{\ephemeralKey}{\mathtt{ephemeralKey}}
 \newcommand{\encCiphertexts}{\mathtt{encCiphertexts}}
+\newcommand{\RandomSeed}{\mathsf{randomSeed}}
 \newcommand{\randomSeed}{\mathtt{randomSeed}}
 \newcommand{\rt}{\mathsf{rt}}
 \newcommand{\Varies}{\textit{Varies}}
@@ -687,8 +690,10 @@ An argument to a function can determine other argument or result types.
 
 The following integer constants will be instantiated in \crossref{constants}:
 $\MerkleDepth$, $\NOld$, $\NNew$, $\MerkleHashLength$, $\GeneralCRHLength$,
-$\PRFOutputLength$, $\AuthPrivateLength$, $\NoteAddressPreRandLength$,
-$\MAXMONEY$.
+$\PRFOutputLength$, $\NoteCommitRandLength$, $\RandomSeedLength$, $\AuthPrivateLength$,
+$\NoteAddressPreRandLength$, $\MAXMONEY$. The bit sequence constant
+$\Uncommitted \typecolon \bitseq{\MerkleHashLength}$ will also be defined in
+that section.
 
 
 \nsection{Concepts}
@@ -1189,7 +1194,7 @@ Either $\vpubOld$ or $\vpubNew$ \MUST be zero.
 \begin{lrbox}{\hsigbox}
 \setchanged
 \begin{bytefield}[bitwidth=0.04em]{1024}
-    \bitbox{256}{$256$-bit $\randomSeed$}
+    \bitbox{256}{$256$-bit $\RandomSeed$}
     \bitbox{256}{\hfill $256$-bit $\nfOld{\mathrm{1}}$\hfill...\;} &
     \bitbox{256}{$256$-bit $\nfOld{\NOld}$} &
     \bitbox{256}{$256$-bit $\joinSplitPubKey$}
@@ -1618,6 +1623,8 @@ Define:
   \item[] $\MerkleHashLength = 256$
   \item[] $\GeneralCRHLength = 256$
   \item[] $\PRFOutputLength = 256$
+  \item[] $\NoteCommitRandLength = 256$
+  \item[] $\RandomSeedLength = 256$
   \item[] $\AuthPrivateLength = 252$
   \item[] $\NoteAddressPreRandLength = 252$
   \item[] $\Uncommitted = \zeros{\MerkleHashLength}$