mirror of https://github.com/zcash/zips.git
Fix a bug in the definition of DefaultDiversifier.
Signed-off-by: Daira Hopwood <daira@jacaranda.org>
This commit is contained in:
parent
2e2200a0bc
commit
f41b95b72f
|
@ -879,6 +879,7 @@ electronic commerce and payment, financial privacy, proof of work, zero knowledg
|
|||
\newcommand{\DiversifyHash}{\mathsf{DiversifyHash}}
|
||||
\newcommand{\DiversifyHashText}{\texorpdfstring{$\DiversifyHash$}{DiversifyHash}}
|
||||
\newcommand{\DefaultDiversifier}{\mathsf{DefaultDiversifier}}
|
||||
\newcommand{\CheckDiversifier}{\mathsf{CheckDiversifier}}
|
||||
\newcommand{\NotUpMySleeve}{U}
|
||||
|
||||
\newcommand{\tx}{\mathsf{tx}}
|
||||
|
@ -3558,8 +3559,16 @@ as above.
|
|||
Let $\first \typecolon (\byte \rightarrow \maybe{T}) \rightarrow \maybe{T}$
|
||||
be as defined in \crossref{concretegrouphashjubjub}.
|
||||
|
||||
Define $\DefaultDiversifier(\sk) :=
|
||||
\first(\fun{i \typecolon \byte}{\DiversifyHash(\truncate{(\DiversifierLength/8)}(\PRFexpand{\sk}([3, i]))) \typecolon \GroupJ})$.
|
||||
Define:
|
||||
\vspace{-2ex}
|
||||
\begin{formulae}
|
||||
\item $\CheckDiversifier(\Diversifier \typecolon \DiversifierType) := \begin{cases}
|
||||
\bot, &\caseif \DiversifyHash(\Diversifier) = \bot \\
|
||||
\Diversifier, &\caseotherwise
|
||||
\end{cases}$
|
||||
\item $\DefaultDiversifier(\sk \typecolon \SpendingKeyType) :=
|
||||
\first\big(\fun{i \typecolon \byte}{\CheckDiversifier(\truncate{(\DiversifierLength/8)}(\PRFexpand{\sk}([3, i]))) \typecolon \GroupJ}\big)$.
|
||||
\end{formulae}
|
||||
|
||||
For a random \spendingKey, $\DefaultDiversifier$ returns $\bot$ with probability approximately $2^{-256}$.
|
||||
|
||||
|
@ -8911,6 +8920,16 @@ found by Brian Warner.
|
|||
\intropart
|
||||
\section{Change History}
|
||||
|
||||
\subparagraph{2018.0-beta-17}
|
||||
|
||||
\begin{itemize}
|
||||
\item No changes to \Sprout.
|
||||
\sapling{
|
||||
\item Correct an error in the definition of $\DefaultDiversifier$.
|
||||
} %sapling
|
||||
\end{itemize}
|
||||
|
||||
\introlist
|
||||
\subparagraph{2018.0-beta-16}
|
||||
|
||||
\begin{itemize}
|
||||
|
|
Loading…
Reference in New Issue