mention scalability, cite RSCoin on that

doc/paper/taler.bib

@@ -27,6 +27,18 @@
     note = {\url{http://eprint.iacr.org/2016/701}},
 }
 
+@inproceedings{danezis2016rscoin,
+  author    = {George Danezis and
+               Sarah Meiklejohn},
+  title     = {Centrally Banked Cryptocurrencies},
+  booktitle = {23nd Annual Network and Distributed System Security Symposium, {NDSS}
+               2016, San Diego, California, USA, February 21-24, 2016},
+  year      = {2016},
+  booktitle  = {23nd Annual Network and Distributed System Security Symposium, {NDSS}
+               2016, San Diego, California, USA, February 21-24, 2016},
+  publisher = {The Internet Society},
+}
+
 @Misc{greece2015cash,
   author =    {Reuters},
   title =     {Greek council recommends 60 euro limit on ATM withdrawals from Tuesday},

doc/paper/taler.tex

@@ -1485,6 +1485,13 @@ these experimental results show that computing-related business costs
 will only marginally contribute to the operational costs of the Taler
 payment system.
 
+Scalability of the design is also not a concern, as the exchange's
+database can be easily shareded over the different public keys as
+desired.  Similar to the RSCoin~\cite{danezis2016rscoin} design, this
+ensures that conflicting transactions end up in the same shard,
+enabling linear scalability of the database operations.  Similarly,
+the cryptographic verification in the frontend can be distributed over
+as many compute nodes as required.
 
 \section{Discussion}