Add some papers, tweak columns.

All citations point to exchage/doc/papers/taler.bib

1 files changed, 68 insertions, 17 deletions

diff --git a/comparison/comparison.tex b/comparison/comparison.tex
index 1fab2a7..cf4886b 100644
--- a/comparison/comparison.tex
+++ b/comparison/comparison.tex
@@ -32,7 +32,7 @@
 \newcommand\Y{\ding{51}} % {\checkmark}
 \newcommand\N{\ding{55}}
 
-\begin{tabular}{r|ccccccccccccc}
+\begin{tabular}{r|cccccccccccccc}
 &
 \rot{Instant enforcement} &
 \rot{Robust anonymity} &
@@ -42,8 +42,10 @@
 \rot{Transferability} &
 \rot{Taxability} &
 %
-\rot{Withdrawal cost} &
-\rot{Deposit cost} &
+% \rot{Withdrawal cost} & \rot{Deposit cost} &
+\rot{Trustless anonymity} &
+\rot{Realistic Exchange Storage} &
+\rot{Cryptographic Batching} &
 \rot{Change} &
 %
 \rot{Robust anonymity} &
@@ -54,27 +56,66 @@
 Taler
 &  \Y & \Y & \Y
 &  \N &  S & \Y
-&  $\log n$ & $\log n$ & ON
+% &  $\log n$ & $\log n$ 
+&  \Y & \Y & \N & ON
 &  \Y & \Y & \Y & Anon
 \\
 % TODO: Just omit this straw-man online Chaum in favor on HINDE
 Chaum Online
 &  \Y &  ? & \Y?
 &  \N &  S & \N
-&  $\log n$ & $\log n$ & ON
+% &  $\log n$ & $\log n$ 
+&  \Y & \Y & \N & ??
 &  \Y? & \N & \N & ?
 \\ 
 HINDE
 &  \Y? & \Y & \Y?
 &  \N &  S & \N
-&  $\log n$ & $\log n$ & ON
+% &  $\log n$ & $\log n$ 
+&  \Y & \Y? & \N & ??
 &  \Y? & \N? & \N? & ? 
 \\
 Chaum Offline
 &  \N &  ? & \Y?
 &  \N &  S & \N?
-&  $\log n$ & $\log n$ & ON 
+% &  $\log n$ & $\log n$ 
+&  \Y & \N? & \N? & OFF
 &  \Y? & \N? & \N? & ?
+\\
+Compact ECash \cite{?compact?}
+&  \N &  ? & \Y?
+&  \N &  S & \N?
+% &  $\log n$ & $\log n$ 
+&  \Y? & \N & W & OFF
+&  \N & \N? & \N? & \N?
+\\
+Martens \cite{Martens2015}
+&  \N &  ? & \Y?
+&  \N &  S & \N?
+% &  $\log n$ & $\log n$ 
+&  \Y? & \N & W & OFF
+&  \N & \N? & \N? & \N?
+\\
+Divisible ECash \cite{CPST-DivisibleMadePractical,CPST-CutDownTheTree}
+&  \N &  ? & \Y?
+&  \N &  S & \N?
+% &  $\log n$ & $\log n$ 
+&  \N & \N & W & OFF
+&  \N & \N? & \N? & \N?
+\\
+Compact Taler
+&  \Y & \Y & \Y
+&  \N &  S & \Y
+% &  $\log n$ & $\log n$ 
+&  \Y & \Y & W & ON
+&  \Y & \Y & \Y & Anon
+\\
+Divisible Taler
+&  \Y & \Y & \Y
+&  \N &  S & \Y
+% &  $\log n$ & $\log n$ 
+&  \N & \Y & WD & ON
+&  \Y & \Y & \Y & Anon
 \\ \hline
 \end{tabular}
 
@@ -132,17 +173,27 @@ Chaum Offline
   \item \textbf{Endorsed.}  Separation of the coin and permission to spend
     it, see \cite{camenisch2007endorsed}.  Allows fair exchange (?).
   \item \textbf{Refunds.}  Anonymous/Deanonymizing/Payment/None/Unspecified
-  \item \textbf{Anonymity Without Trusted Setup / ``Trustless anonymity``.}  A trusted stup is be problematic;
-    while the exchange is fixed, the customers/merchant are not, so
-    distributed key generation isn't always an option.  It makes it hard to instantiate the scheme
-    and hard to trust the deployed scheme.
+
+  \item \textbf{Trustless anonymity}
+    At present, divisible ecash schemes entrust anonymity properties
+    to a trusted setup phase.  Users cannot easily participate in this
+    trusted setup, so they must entrust some party with their anonymity,
+    and instantiating such schemes becomes difficult.
   \item \textbf{Realistic Exchange Storage Requirements.}
-    In schemes that have divisibility, the exchange still needs to
-    store the smallest denomination.  Unless the scheme also has multiple denominations,
-    this storage requirements are unrealistic.
-  \item \textbf{Cryptographic Batching.}  Some schemes allow
-    withdrawing a wallet with $2^\ell$ coins in $O(1)$ with
-    $O(1)$ storage and $O(1)$ batch spending.
+    Both compact and divisible ecash schemes require the exchange store
+    coins only as the smallest denomination to prevent double spending. 
+    In practice, these schemes should be adjusted to store larger
+    denominations or else the exchange's storage requirments would
+    become unrealistic, but doing so 
+  \item \textbf{Cryptographic Batching.}
+    Compact ECash schemes provide withdrawal operations that extract 
+    many coins with one single withdrawal, reducing overall bandwidth
+    for fixed denomination values, but not computation.  %% VERIFY
+    Divisible ECash schemes batch both withdrawal and deposit operations,
+    providing greater bandwith reduction, and possibly computaiton
+    reduction.  These savings are limited however by the exchange's
+    storage requirments, and divisible schemes depend upon trusted setup
+    for their anonymity properties. 
 \end{itemize}