  In this paper we explore a method to create anonymous services on top of the
STORK framework, to be used for electronic surveys or elections.
  The STORK project aims to realize a single electronic identification and
authentication area across Europe. For verifiable and anonymous voting, users
should be authenticated with their e-id (to prevent repeated voting) but the
votes should also be anonymous. This is achieved using blind signatures and an
onion routing system similar to the one used in TOR.
  In the paper we describe the anonymous voting protocol in detail, we analyze
a reference implementation and, finally, we highlight potential weaknesses and
propose some improvements.
