October 9 – 14 , 2005, Dagstuhl Seminar 05411

Anonymous Communication and its Applications


Shlomi Dolev (Ben Gurion University – Beer Sheva, IL)
Rafail Ostrovsky (UCLA, US)
Andreas Pfitzmann (TU Dresden, DE)

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Press Room

Anonymität im Zeitalter der mobilen Kommunikation (Pressemitteilung vom 13.09.2005)


Throughout history encryption was used to hide the contents of transmitted data. The rapid growth in the use of the Internet only increased the necessity of encryption. However, encryption does not hide all relevant information, for example, it does not hide the identity of the communicating parties. That is, it does not prevent traffic analysis.

Modern cryptographic techniques are extremely good in concealing all the contents of data, by means of encrypting the messages. However, concealing the contents of the message does not hide the fact that some message was sent from or received by a particular site. Thus, if some location (or network node) A is sending and/or receiving a lot of messages to/from B, and if an adversary can monitor this fact, then even if the adversary does not understand what these messages mean, just the fact that there are a lot of messages between A and B reveals that and when they cooperate.

The objective of anonymous communication is to show how to hide, in an efficient manner, the identity of users who transmit (or receive) a data to (or from, respectively) other sites in the network. The workshop is aimed both at discussing various techniques of anonymity and also exploring applications of anonymity.

The question of anonymous communication was studied both by academia and industry for more than two decades.

The seminar will serve as a platform for establishing a community that blends theoreticians and practitioners interested in the important aspect of anonymity in communication and its applications.

We plan to discuss, study and investigate several aspects of the fields including:

  • Anonymous communication in the Internet
  • Anonymous communication in sensor and ad-hoc networks
  • Anonymous communication to hide control and command
  • Privacy issues and the social interests in anonymous communication
  • Unidirectional encryption schemes

The scientific relevance of the field to the academia and industry is bold: there are leading researchers in cryptography and networking that are interested and active in the area.

The results so far include possibility/impossibility results, efficiency issues, and system architectures that support annonimicity.

The Dagstuhl seminar will be the first time in which researchers and practitioners in the area are gathered to interact, no doubt that the meeting will boost the activity in the area.


In the series Dagstuhl Reports each Dagstuhl Seminar and Dagstuhl Perspectives Workshop is documented. The seminar organizers, in cooperation with the collector, prepare a report that includes contributions from the participants' talks together with a summary of the seminar.


Download overview leaflet (PDF).

Dagstuhl's Impact

Please inform us when a publication was published as a result from your seminar. These publications are listed in the category Dagstuhl's Impact and are presented on a special shelf on the ground floor of the library.


Furthermore, a comprehensive peer-reviewed collection of research papers can be published in the series Dagstuhl Follow-Ups.