"Balancing Privacy and Regulation"

					Abstract

In certain applications the issue of privacy (anonymity) is a central one. 
A few examples are voting, auctions, anonymous payments/transactions 
(such as trading stock), anonymous mails, or authorization/authentication 
of sensitive documents.

In most cases, however, unconditional anonymity contradicts either  
regulation or policy guidelines: e.g., payments need to be traceable 
by the Federal Government (for both tax reasons and prevention of fraud/abuse), 
anonymous mails need to be traced if they are offending, participants in auctions 
need to be identified if they default, etc.   

Fortunately, recent cryptographic advances allow anonymous systems to be 
implemented such that a trusted party (or collection of parties) can selectively 
break the system's anonymity. Therefore, e.g., a malicious e-mail can be traced 
to its sender, without compromising anonymity of the rest of the system.


We present various settings where privacy and tracing need to be balanced 
and discuss the methods used for achieving these seemingly contradicting
goals. 

Open research questions conclude the talk.