Marc Rennhard Bernhard Plattner Practical Anonymity for the Masses with MorphMix. 233-250 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3110&spage=233 2004 conf/fc/2004 Financial Cryptography db/conf/fc/fc2004.html#RennhardP04