diff --git a/protocol/protocol.tex b/protocol/protocol.tex index d69dfd47..8ef26d63 100644 --- a/protocol/protocol.tex +++ b/protocol/protocol.tex @@ -5747,8 +5747,8 @@ $\MerkleCRHSapling \typecolon \MerkleLayerSapling \times \MerkleHashSapling \tim \vspace{1ex} \textbf{Note:}\;\; The prefix $l$ provides domain separation between inputs at different layers of the -\noteCommitmentTree. It is distinct from the $\NoteCommitSaplingAlg$ prefix -as noted in \crossref{concretewindowedcommit}.} %sapling +\noteCommitmentTree. $\NoteCommitSaplingAlg$, like $\PedersenHash$, is defined in terms of $\PedersenHashToPoint$, +but using a prefix that cannot collide with a layer prefix, as noted in \crossref{concretewindowedcommit}.} %sapling \subsubsubsection{\hSigText{} \HashFunction} \label{hsigcrh} @@ -6913,11 +6913,13 @@ instantiated as follows using $\WindowedPedersenCommitAlg$: \vspace{-2ex} \begin{pnotes} - \item The prefix $\ones{6}$ distinguishes the use of $\WindowedPedersenCommitAlg$ in - $\NoteCommitSaplingAlg$ from the layer prefix used in $\MerkleCRHSapling$ (see - \crossref{merklecrh}). The latter is a $6$-bit little-endian encoding of an integer - in $\range{0}{\MerkleDepthSapling-1}$; because $\MerkleDepthSapling < 64$, this - cannot collide with $\ones{6}$. + \item $\MerkleCRHSapling$ is also defined in terms of $\PedersenHashToPoint$ + (see \crossref{merklecrh}). The prefix $\ones{6}$ distinguishes the use of + $\WindowedPedersenCommitAlg$ in + $\NoteCommitSaplingAlg$ from the layer prefix used in $\MerkleCRHSapling$. + That layer prefix is a $6$-bit little-endian encoding of an integer + in the range $\range{0}{\MerkleDepthSapling-1}$; because $\MerkleDepthSapling < 64$, + it cannot collide with $\ones{6}$. \item The arguments to $\NoteCommitSapling{}$ are in a different order to their encodings in $\WindowedPedersenCommit{}$. There is no particularly good reason for this. \end{pnotes} @@ -9787,6 +9789,8 @@ Peter Newell's illustration of the Jubjub bird, from \cite{Carroll1902}. \item Address some of the findings of the QED-it report: \begin{itemize} \item Improved cross-referencing in \crossref{concretepedersenhash}. + \item Clarify the notes concerning domain separation of prefixes in + \crossref{saplingmerklecrh} and \crossref{concretesaplingnotecommit}. \end{itemize} } %sapling \item Add the QED-it report to the acknowledgements.