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Replace coin singing key with denomination key

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This commit is contained in:
Jeff Burdges 2016-05-22 16:55:11 +02:00
parent 9a0fb5c7e2
commit 619eb44b87
1 changed files with 12 additions and 12 deletions
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24
doc/paper/taler.tex
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@ -49,7 +49,7 @@
% - refreshing = customer-exchange-customer
% - dirty coin = coin with exposed public key
% - fresh coin = coin that was refreshed or is new
% - coin signing key = exchange's online key used to (blindly) sign coin
% - denomination key = exchange's online key used to (blindly) sign coin
% - message signing key = exchange's online key to sign exchange messages
% - exchange master key = exchange's key used to sign other exchange keys
% - owner = entity that knows coin private key
@ -540,21 +540,21 @@ to the state.
A \emph{coin} in Taler is a public-private key pair which derives its
financial value from a signature over the coin's public key by a exchange.
The exchange is expected to have multiple {\em coin signing key} pairs
The exchange is expected to have multiple {\em denomination key} pairs
available for signing, each representing a different coin
denomination.
These coin signing keys have an expiration date, before which any coins
These denomination keys have an expiration date, before which any coins
signed with it must be spent or refreshed. This allows the exchange to
eventually discard records of old transactions, thus limiting the
records that the exchange must retain and search to detect double-spending
attempts. Furthermore, the exchange is expected to use each coin signing
attempts. Furthermore, the exchange is expected to use each denomination
key only for a limited number of coins.
% for example by limiting its use to sign coins to a week or a month.
In this way, if a private coin signing key were to be compromised,
In this way, if a private denomination key were to be compromised,
the exchange would detect this once more coins were redeemed than the total
that was signed into existence using that coin signing key.
that was signed into existence using that denomination key.
In this case, the exchange could allow authentic customers to exchange their
unspent coins that were signed with the compromised private key,
while refusing further anonymous transactions involving those coins.
@ -638,7 +638,7 @@ The owner of such a {\em dirty} coin might therefore want to exchange it
for a {\em fresh} coin to ensure unlinkability with future transactions.
% with the previous operation.
Even if a coin is not dirty, the owner of a coin may want to exchange it
if the respective coin signing key is about to expire. All of these
if the respective denomination key is about to expire. All of these
operations are supported with the {\em coin refreshing protocol}, which
allows the owner of a coin to {\em melt} it for fresh coins of the same
value with a new public-private key pairs. Refreshing does not use the
@ -682,7 +682,7 @@ in a different context.
The exchange has an {\em online message signing key} used for signing
messages, as opposed to coins. The exchange's long-term offline key is used
to certify both the coin signing keys and the online message signing key
to certify both the denomination keys and the online message signing key
of the exchange. The exchange's long-term offline key is assumed to be known to
both customers and merchants and is certified by the auditors.
@ -708,7 +708,7 @@ the exchange:
\begin{enumerate}
\item The customer identifies a exchange with an auditor-approved
coin signing public-private key pair $K := (K_s, K_p)$
denomination public-private key pair $K := (K_s, K_p)$
and randomly generates:
\begin{itemize}
\item withdrawal key $W := (w_s,W_p)$ with private key $w_s$ and public key $W_p$,
@ -1396,9 +1396,9 @@ indicate the application of a function $f$ to one or more arguments. Records of
data being committed to disk are represented in between $\langle\rangle$.
\begin{description}
\item[$K_s$]{Private (RSA) key of the exchange used for coin signing}
\item[$K_p$]{Public (RSA) key corresponding to $K_s$}
\item[$K$]{Public-priate (RSA) coin signing key pair $K := (K_s, K_p)$}
\item[$K_s$]{Denomination private (RSA) key of the exchange used for coin signing}
\item[$K_p$]{Denomination public (RSA) key corresponding to $K_s$}
\item[$K$]{Public-priate (RSA) denomination key pair $K := (K_s, K_p)$}
\item[$b$]{RSA blinding factor for RSA-style blind signatures}
\item[$B_b()$]{RSA blinding over the argument using blinding factor $b$}
\item[$U_b()$]{RSA unblinding of the argument using blinding factor $b$}