taler/exchange
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

clarify withdraw existing response lookup

Browse Source
This commit is contained in:
Florian Dold 2017-05-17 16:53:36 +02:00
parent 191bcd67f8
commit e53a736dca
No known key found for this signature in database
GPG Key ID: D2E4F00F29D02A4B
2 changed files with 7 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
doc/paper/taler.tex
View File

@ -838,10 +838,9 @@ interaction with the exchange:
the exchange to request withdrawal of $C$; here, $B_b$ denotes the exchange to request withdrawal of $C$; here, $B_b$ denotes
Chaum-style blinding with blinding factor $b$. Chaum-style blinding with blinding factor $b$.
\item \item
The exchange checks if the same withdrawal request was issued before; The exchange checks its database if there is an existing withdraw record $\langle S_W(B), x \rangle$
in this case, it sends a Chaum-style blind signature $S_K(B)$ with with existing withdraw response $x$; in this case it sends back $x$.\\
private key $K_s$ to the customer. \\ Otherwise if this is a fresh withdrawal request, the exchange performs the following transaction:
If this is a fresh withdrawal request, the exchange performs the following transaction:
\begin{enumerate} \begin{enumerate}
\item checks if the reserve $W_p$ has sufficient funds \item checks if the reserve $W_p$ has sufficient funds
for a coin of value corresponding to $K$, for a coin of value corresponding to $K$,
@ -850,7 +849,7 @@ interaction with the exchange:
for future reference, for future reference,
\item deducts the amount corresponding to $K$ from the reserve, \item deducts the amount corresponding to $K$ from the reserve,
\end{enumerate} \end{enumerate}
and then sends $S_K(B)$ to the customer. and then sends Chaum-style blind signature $S_K(B)$ to the customer.
If the guards for the transaction fail, the exchange sends a descriptive If the guards for the transaction fail, the exchange sends a descriptive
error back to the customer, with proof that it operated correctly. error back to the customer, with proof that it operated correctly.
Assuming the signature was valid, this would involve showing the transaction Assuming the signature was valid, this would involve showing the transaction

3
doc/paper/taler_FC2017.txt
View File

@ -150,6 +150,9 @@ Specific comments:
point: 2nd line also reads as “if the same withdrawal request was issued before point: 2nd line also reads as “if the same withdrawal request was issued before
the exchange will send S_K(B)” the exchange will send S_K(B)”
> We added some clarification that the exchange looks up if the request
> already exists in their database.
- Section 4.2, it seems that a customer can use a coin of value say $10 to - Section 4.2, it seems that a customer can use a coin of value say $10 to
multiple transactions of <= $10 in total. I.e. it can first a pay a merchant multiple transactions of <= $10 in total. I.e. it can first a pay a merchant
M1 $2 and then a merchant M2 another $5 dollars. In that case the exchange can M1 $2 and then a merchant M2 another $5 dollars. In that case the exchange can