Specifying cryptographic binding of Pours to the containing transaction more explicitly, without Bitcoin Script.

Needs to define how SIGHASH_ALL covers Pours.

protocol/protocol.tex

@@ -231,8 +231,8 @@
 \newcommand{\vpubNewField}{\mathtt{vpub\_new}}
 \newcommand{\vsum}[2]{\smashoperator[r]{\sum_{#1}^{#2}}}
 \newcommand{\anchorField}{\mathtt{anchor}}
-\newcommand{\scriptSig}{\mathtt{scriptSig}}
-\newcommand{\scriptPubKey}{\mathtt{scriptPubKey}}
+\newcommand{\malleabilitySig}{\mathtt{malleabilitySig}}
+\newcommand{\malleabilityPubKey}{\mathtt{malleabilityPubKey}}
 \newcommand{\serials}{\mathtt{serials}}
 \newcommand{\commitments}{\mathtt{commitments}}
 \newcommand{\ephemeralKey}{\mathtt{ephemeralKey}}
@@ -765,11 +765,9 @@ into the value pool.
 some block height in the past, or the merkle root produced by a previous pour in
 this transaction. \sean{We need to be more specific here.}
 
-\item $\scriptPubKey$ which is a \script that creates conditions for acceptance of a
-\PourDescription in a transaction.
+\item $\malleabilityPubKey$ which is a ecdsa public key used to bind a Pour to the containing transaction.
 
-\item $\scriptSig$ which is a \script used to satisfy the conditions of the
-$\scriptPubKey$.
+\item $\malleabilitySig$ which is an ecdsa signature used to bind a Pour to the containing transaction.
 
 \item $\serials$ which is an $\NOld$ size sequence of serials $\snOld{\allOld}$.
 
@@ -813,7 +811,7 @@ $\PourDescription$.
 	\bitbox{256}{\hfill 256 bit $\snOld{\mathrm{1}}$\hfill...\;} &
 	\bitbox{256}{256 bit $\snOld{\NOld}$} &
 	\bitbox{256}{$\RandomSeed$}
-	\bitbox{256}{$\scriptPubKey$}
+	\bitbox{256}{$\malleabilityPubKey$}
 \end{bytefield}
 \end{lrbox}
 
@@ -832,9 +830,9 @@ identified by that previous $\PourDescription$'s $\anchor$.
 
 \subparagraph{Non-malleability}
 
-A \PourDescription is valid if the script formed by appending $\scriptPubKey$ to 
-$\scriptSig$ returns $true$. The $\scriptSig$ is cryptographically bound to 
-$\PourProof$.
+A \PourDescription is valid if $\malleabilitySig$ over the {SIGHASH\_ALL} transaction hash is signed by the associated $\malleabilityPubKey$. The $\malleabilitySig$ is cryptographically bound to $\PourProof$.
+
+\nathan{FIXME: The {SIGHASH\_ALL} definition must be extended to cover the appropriate Pour descriptor fields.}
 
 \subparagraph{Balance}