criterea

1 files changed, 11 insertions, 0 deletions

diff --git a/comparison/comparison.tex b/comparison/comparison.tex
index b47b2bc..1fab2a7 100644
--- a/comparison/comparison.tex
+++ b/comparison/comparison.tex
@@ -113,10 +113,14 @@ Chaum Offline
   \item \textbf{Withdrawal cost.}
     Asymptotic time and storage costs for the wallet during and after withdrawal.
     Also frequently bandwidth costs for the withdrawal operation.  %TODO: Details?
+    FIXME: Do we have a rigorous definition for this?  Literature
+    only uses big-O for batched withdrawal/deposit.
   \item \textbf{Deposit costs.}
     Asymptotic time and storage costs for the exchange's double spending
     protections required during deposit.   
     Frequently ignored, especially in ``constant time'' schemes.
+    FIXME: Do we have a rigorous definition for this?  Literature
+    only uses big-O for batched withdrawal/deposit.
   \item \textbf{Change/Divisibility.}
     Which mechanism is used for divisibility?  (None/OFFline/ONline).
   \item \textbf{Robustness under network failures.} 
@@ -132,6 +136,13 @@ Chaum Offline
     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{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.
 \end{itemize}