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Merge branch '738.fix-internalh-collision.0' into 406.viewing-keys.1 

Signed-off-by: Daira Hopwood <daira@jacaranda.org>
This commit is contained in:
Daira Hopwood 2016-02-26 00:17:19 +00:00
parent 1d03b32575 e20d0dd437
commit f0c24c113e
2 changed files with 11 additions and 34 deletions
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@ -175,8 +175,6 @@
\newcommand{\SHAOrig}{\term{SHA-256}}
\newcommand{\cm}{\mathsf{cm}}
\newcommand{\cmNew}[1]{\mathsf{{cm}^{new}_\mathnormal{#1}}}
\newcommand{\InternalHashK}{\mathsf{k}}
\newcommand{\InternalHash}{\mathsf{InternalH}}
\newcommand{\Leading}[1]{\mathtt{Leading}_{#1}}
\newcommand{\ReplacementCharacter}{\textsf{U+FFFD}}
\newcommand{\CryptoBoxSeal}{\mathsf{crypto\_box\_seal}}
@ -477,41 +475,20 @@ of $\COMM{\CoinCommitS}$ does not use it.
\subsubsection{Coin Commitments}
The underlying $\Value$ and $\AuthPublic$ are blinded with $\CoinAddressRand$
and $\CoinCommitRand$ using the collision-resistant hash function $\CRH$ in a
multi-layered process. The resulting hash $\cm = \CoinCommitment(\Coin{})$.
\newsavebox{\ihbox}
\begin{lrbox}{\ihbox}
\begin{bytefield}[bitwidth=0.08em]{512}
\bitbox{256}{256 bit $\AuthPublic$} &
\bitbox{256}{256 bit $\CoinAddressRand$}
\end{bytefield}
\end{lrbox}
\newsavebox{\ihkbox}
\begin{lrbox}{\ihkbox}
\begin{bytefield}[bitwidth=0.08em]{512}
\bitbox{384}{384 bit $\CoinCommitRand$} &
\bitbox{128}{$\Leading{128}(\InternalHash)$}
\end{bytefield}
\end{lrbox}
and $\CoinCommitRand$ using the collision-resistant hash function $\FullHash$.
The resulting hash $\cm = \CoinCommitment(\Coin{})$.
\newsavebox{\cmbox}
\begin{lrbox}{\cmbox}
\begin{bytefield}[bitwidth=0.08em]{512}
\bitbox{64}{64 bit $\Value$} &
\bitbox{192}{192 bit padding} &
\bitbox{256}{256 bit $\InternalHashK$}
\begin{bytefield}[bitwidth=0.045em]{832}
\bitbox{256}{256 bit $\AuthPublic$} &
\bitbox{96}{64 bit $\Value$} &
\bitbox{256}{256 bit $\CoinAddressRand$}
\bitbox{256}{256 bit $\CoinCommitRand$} &
\end{bytefield}
\end{lrbox}
\begin{equation*}
\begin{aligned}
\InternalHash &:= \CRHbox{\ihbox} \\
\InternalHashK &:= \CRHbox{\ihkbox} \\
\cm &:= \CRHbox{\cmbox}
\end{aligned}
\end{equation*}
$\cm := \FullHashbox{\cmbox}$
\subsubsection{Serial numbers}
@ -1185,13 +1162,13 @@ The raw encoding of a \coinPlaintext $(\AuthPublic, \Value, \CoinAddressRand,
\CoinCommitRand, \Memo)$ consists of, in order:
\begin{equation*}
\begin{bytefield}[bitwidth=0.03em]{1480}
\begin{bytefield}[bitwidth=0.032em]{1352}
\changed{
\bitbox{88}{$\TransmitPlaintextVersionByte$}&
\bitbox{256}{$\AuthPublic$ (32 bytes)}&
&}\bitbox{168}{$\Value$ (8 bytes)} &
\bitbox{256}{$\CoinAddressRand$ (32 bytes)} &
\bitbox{384}{$\CoinCommitRand$ (48 bytes)} &
\bitbox{256}{$\CoinCommitRand$ (32 bytes)} &
\changed{\bitbox{512}{$\Memo$ (64 bytes)}}
\end{bytefield}
\end{equation*}
@ -1204,7 +1181,7 @@ encoding of a \coinPlaintext.
}
\item 8 bytes specifying a big-endian encoding of $\Value$.
\item 32 bytes specifying $\CoinAddressRand$.
\item 48 bytes specifying $\CoinCommitRand$.
\item 32 bytes specifying $\CoinCommitRand$.
\changed{
\item 64 bytes specifying $\Memo$.
}