diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/paper/taler.bib | 32 | ||||
| -rw-r--r-- | doc/paper/taler.tex | 28 | 
2 files changed, 49 insertions, 11 deletions
diff --git a/doc/paper/taler.bib b/doc/paper/taler.bib index 67bf07c2..66330925 100644 --- a/doc/paper/taler.bib +++ b/doc/paper/taler.bib @@ -99,14 +99,30 @@  @inproceedings{Camenisch05compacte-cash, -    author = {Jan Camenisch and Susan Hohenberger and Anna Lysyanskaya}, -    title = {Compact e-cash}, -    booktitle = {In EUROCRYPT, volume 3494 of LNCS}, -    year = {2005}, -    pages = {302--321}, -    publisher = {Springer-Verlag} -    url = {http://cs.brown.edu/~anna/papers/chl05-full.pdf}, -    url_citeseerx = {http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.136.4640} +  author = {Jan Camenisch and Susan Hohenberger and Anna Lysyanskaya}, +  title = {Compact e-cash}, +  booktitle = {In EUROCRYPT, volume 3494 of LNCS}, +  year = {2005}, +  pages = {302--321}, +  publisher = {Springer-Verlag}, +  url = {http://cs.brown.edu/~anna/papers/chl05-full.pdf}, +  url_citeseerx = {http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.136.4640} +} + + +@Inbook{ST99, +  author="Sander, Tomas and Ta-Shma, Amnon", +  editor="Wiener, Michael", +  title="Auditable, Anonymous Electronic Cash", +  bookTitle="Advances in Cryptology --- CRYPTO' 99: 19th Annual International Cryptology Conference Santa Barbara, California, USA, August 15--19, 1999 Proceedings", +  year="1999", +  publisher="Springer Berlin Heidelberg", +  address="Berlin, Heidelberg", +  pages="555--572", +  isbn="978-3-540-48405-9", +  doi="10.1007/3-540-48405-1_35", +  doi_url="http://dx.doi.org/10.1007/3-540-48405-1_35", +  url = {http://www.cs.tau.ac.il/~amnon/Papers/ST.crypto99.pdf"}  } diff --git a/doc/paper/taler.tex b/doc/paper/taler.tex index 19b1b19f..c1b38ae1 100644 --- a/doc/paper/taler.tex +++ b/doc/paper/taler.tex @@ -292,15 +292,37 @@ multiple transactions can be linked to each other.  Performing fractional payments using $k$-show signatures is also   rather expensive. -% For longer non-conference version : -% -Add note on Carmenisch's compact e-cash withdrawals \cite{Camenisch05compacte-cash} -% -Add note on Merkle tree based scheme that inspired Zerocash +In pure blind signature based schemes like Taler, withdrawal and spend +operations require bandwidth logarithmic in the value being withdrawn +or spent.  In \cite{Camenisch05compacte-cash}, there is a zero-knoledge +scheme that improves upon this, requiring only constant bandwidth for +withdrawals and spend operations, but sadly the exchanges' storage and +search costs become lienar in the total value of all transactions.  +In princile, one could correct this by adding multiple denominations,  +an open problem stated already in \cite{Camenisch05compacte-cash}. +As described, the scheme employs offline double spending protection, +which inherently makes it fragile and create an wholey unneccasry  +deanonymization risk.  We believe the offline protection from double +spending could be removed, thus switching the scheme to only protection +against online doulbe spending, like Taler.  +Along with fixing these two issues, an interesting applied research project +would be to add partial spending and a form of Taler's refresh protocol. +At present, we feel these relatively new cryptographic techniques incur +unacceptable financial risks to the exchange, due to underdeveloped +implementation practice. + +In this vein, there are pure also zero-knoledge proof based schemes +like \cite{ST99}, and subsequently Zerocash~\cite{zerocash}, and maybe +varations on BOLT~\cite{BOLT}, that avoid using any denomination-like +constructs, slightly reducing metadata leakage.  At present, these all +incur excessive bandwidth or computational costs however.  %Some argue that the focus on technically perfect but overwhelmingly  %complex protocols, as well as the the lack of usable, practical  %solutions lead to an abandonment of these ideas by  %practitioners~\cite{selby2004analyzing}. +% FIXME: Move to top of section?  % FIXME: ask OpenCoin dev's about this! Then make statement firmer!  To our knowledge, the only publicly available effort to implement  Chaum's idea is Opencoin~\cite{dent2008extensions}.  However, Opencoin  | 
