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Switch to X for exchanges

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This commit is contained in:
Jeff Burdges 2016-08-09 00:48:08 +02:00
parent 1a2ecef44b
commit bbeef4560d
1 changed files with 21 additions and 20 deletions
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doc/paper/taler.tex
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@ -684,10 +684,10 @@ with signature $\widetilde{C} := S_K(\FDH_K(C_p))$
\begin{enumerate} \begin{enumerate}
\item\label{contract} \item\label{contract}
Let $\vec{D} := D_1, \ldots, D_n$ be the list of exchanges accepted by Let $\vec{X} := \langle X_1, \ldots, X_n \rangle$ denote the list of
the merchant where each $D_j$ is a exchange's public key. exchanges accepted by the merchant where each $X_j$ is a exchange's
The merchant creates a digitally signed contract public key. The merchant creates a digitally signed contract
$\mathcal{A} := S_M(m, f, a, H(p, r), \vec{D})$ $\mathcal{A} := S_M(m, f, a, H(p, r), \vec{X})$
where $m$ is an identifier for this transaction, $a$ is data relevant where $m$ is an identifier for this transaction, $a$ is data relevant
to the contract indicating which services or goods the merchant will to the contract indicating which services or goods the merchant will
deliver to the customer, $f$ is the price of the offer, and deliver to the customer, $f$ is the price of the offer, and
@ -697,11 +697,11 @@ with signature $\widetilde{C} := S_K(\FDH_K(C_p))$
\item\label{deposit} \item\label{deposit}
The customer should already possess a coin issued by a exchange that is The customer should already possess a coin issued by a exchange that is
accepted by the merchant, meaning $K$ should be publicly signed by accepted by the merchant, meaning $K$ should be publicly signed by
some $D_j \in \{D_1, D_2, \ldots, D_n\}$, and has a value $\geq f$. some $X_j$ from $\vec{X}$, and has a value $\geq f$.
\item The customer generates a \emph{deposit-permission} $\mathcal{D} := \item The customer generates a \emph{deposit-permission} $\mathcal{D} :=
S_c(\widetilde{C}, m, f, H(a), H(p,r), M_p)$ S_c(\widetilde{C}, m, f, H(a), H(p,r), M_p)$
and sends $\langle \mathcal{D}, D_j\rangle$ to the merchant, and sends $\langle \mathcal{D}, X_j\rangle$ to the merchant,
where $D_j$ is the exchange which signed $K$. where $X_j$ is the exchange which signed $K$.
\item The merchant gives $(\mathcal{D}, p, r)$ to the exchange, thereby \item The merchant gives $(\mathcal{D}, p, r)$ to the exchange, thereby
revealing $p$ only to the exchange. revealing $p$ only to the exchange.
\item The exchange validates $\mathcal{D}$ and checks for double spending. \item The exchange validates $\mathcal{D}$ and checks for double spending.
@ -1227,8 +1227,8 @@ data being committed to disk are represented in between $\langle\rangle$.
\item[$\widetilde{C}$]{Exchange signature $S_K(C_p)$ indicating validity of a fresh coin (with key $C$)} \item[$\widetilde{C}$]{Exchange signature $S_K(C_p)$ indicating validity of a fresh coin (with key $C$)}
\item[$n$]{Number of exchanges accepted by a merchant} \item[$n$]{Number of exchanges accepted by a merchant}
\item[$j$]{Index into a set of accepted exchanges, $i \in \{1,\ldots,n\}$} \item[$j$]{Index into a set of accepted exchanges, $i \in \{1,\ldots,n\}$}
\item[$D_j$]{Public key of a exchange (not used to sign coins)} \item[$X_j$]{Public key of a exchange (not used to sign coins)}
\item[$\vec{D}$]{Vector of $D_j$ signifying exchanges accepted by a merchant} \item[$\vec{X}$]{Vector of $X_j$ signifying exchanges accepted by a merchant}
\item[$a$]{Complete text of a contract between customer and merchant} \item[$a$]{Complete text of a contract between customer and merchant}
\item[$f$]{Amount a customer agrees to pay to a merchant for a contract} \item[$f$]{Amount a customer agrees to pay to a merchant for a contract}
\item[$m$]{Unique transaction identifier chosen by the merchant} \item[$m$]{Unique transaction identifier chosen by the merchant}
@ -1328,19 +1328,20 @@ lock permission expires to ensure that no other merchant redeems the
coin first. coin first.
\begin{enumerate} \begin{enumerate}
\item\label{offer2} The merchant sends an \emph{offer:} $\langle S_M(m, f), \item\label{offer2} The merchant sends an \emph{offer:}
\vec{D} \rangle$ containing the price of the offer $f$, a transaction $\langle S_M(m, f), \vec{X} \rangle$ containing the price of the offer $f$,
ID $m$ and the list of exchanges $D_1, \ldots, D_n$ accepted by the merchant a transaction ID $m$ and the list of exchanges
where each $D_j$ is a exchange's public key. $\vec{X} = \langle X_1, \ldots, X_n \rangle$ accepted by the merchant,
where each $X_j$ is a exchange's public key.
\item\label{lock2} The customer must possess or acquire a coin $\widetilde{C}$ \item\label{lock2} The customer must possess or acquire a coin $\widetilde{C}$
signed by a exchange that is signed by a exchange that is accepted by the merchant,
accepted by the merchant, i.e. $K$ should be signed by some $D_j i.e.\ $K$ should be signed by some $X_j$ and has a value $\geq f$.
\in \{D_1, D_2, \ldots, D_n\}$, and has a value $\geq f$.
Customer then generates a \emph{lock-permission} $\mathcal{L} := Customer then generates a \emph{lock-permission}
S_c(\widetilde{C}, t, m, f, M_p)$ where $t$ specifies the time until which the $\mathcal{L} := S_c(\widetilde{C}, t, m, f, M_p)$ where
lock is valid and sends $\langle \mathcal{L}, D_j\rangle$ to the merchant, $t$ specifies the time until which the lock is valid and sends
where $D_j$ is the exchange which signed $K$. $\langle \mathcal{L}, X_j\rangle$ to the merchant,
where $X_j$ is the exchange which signed $K$.
\item The merchant asks the exchange to apply the lock by sending $\langle \item The merchant asks the exchange to apply the lock by sending $\langle
\mathcal{L} \rangle$ to the exchange. \mathcal{L} \rangle$ to the exchange.
\item The exchange validates $\widetilde{C}$ and detects double spending \item The exchange validates $\widetilde{C}$ and detects double spending