Old photograph. (2)	George Danezis

Myself

I am a post-doctoral researcher at Microsoft Research Cambridge. My key interests relate to the areas of computer security, privacy, and in particular anonymous communications, traffic analysis, and peer-to-peer security.

Between 2005 and 2007 I was a post-doctoral visiting fellow at Prof. Bart Preneel's COSIC group at K.U.Leuven, Belgium. Until 2005 I have been a research assistant in the Security Group, of the Computer Laboratory of the University of Cambridge, working on anonymous communications, peer-to-peer networks and censorship resistance. I also got my Ph.D, M.A. and B.A at the Cambridge University, Computer Laboratory under the supervision of Prof. Ross J. Anderson.

Latest news

• Conspicuous Chatter is my new blog, where I discuss issue related to anonymous communications and traffic analysis. My notes on academic work I read are also there, along with previews of my own work.
• Slides from my talk "Anonymity and Cryptography" presented at WEWoRC 2007.
• Richard Clayton and myself just authored a book chapter providing an Introduction to Traffic Analysis. This is to appear in a collective volume on privacy technology.
• Two videos of lectures I gave:
• An Introduction to Traffic Analysis. An Introduction to Traffic Analysis Speech by George Danezis at 23C3.
• Viewing Privacy as a Security Property. Microsoft Research, February 17, 2006
• Two new manuscripts are under review: Covert Communications Despite Traffic Data Retention and Private Yet Abuse Resistant Open Publishing (with Ben Laurie).

Research

• We have done some work on the Economics of mass surveillance and the (questionable) value of anonymous communications. We look at target selection strategies for maximizing surveillance (or disruption) return based on data collected from a real social network. It turns out that current anonymous communications solutions do not pretoect too well against such target selection.
• We organized (with Phillipe Golle) the 6th Workshop on Privacy Enhancing Technologies (PET 2006) in Cambridge,UK. The program is available. The proceedings are published by Springer. Previously I have been in charge of PET2005 with David Martin.
• I have been working with Richard and Markus assesing real life systems that provide Anonymous services. We document real patterns of failure in these systems, and work towards a security model for pseudonymity [pdf,html].
• Some people have been sending me anonymous emails without including a reply block, therefore not giving me the ability to answer their questions. For this reason I have built a new page with replies to anonymous emails. Make sure you access it using a suitable anonymizing proxy!

• What can you do with traffic analysis? Often people ask me the same question so I have a presentation and a background paper introducing the topic. They were both prepared for my talk at the Santa's Crypto Get-together in Prague, December 2005.
• In order to better evaluate anonymous systems and attacks against the anonymity properties of systems, Andrei Serjantov and I, propose a new definition of the "Anonymity set". We move away from the classic world of set theory toward a definition that takes into account probability distributions over different participants and redefine anonymity sets using entropy and other tools borrowed from information theory. This metric allows a better qualitative understanding of anonymity and allows researchers to move beyond the typical all-or-nothing approach to these systems and their failures. The paper that describes these definitions is available in pdf format. It appeared at PET2002, and got an award at PET2003.
• Lately I have been working on traffic Analysis, and a preliminary poster of some results appeared at the "Workshop on Privacy and Identity in the Information Society: Systemic Risks" (5-6th February 2002).
• Along with others, we are collaborating to design and build MixMinion, the next generation of anonymous remailers. They should support sender-receiver anonymous communications, and support for forward security on the links. The development lists are public, and the first design document is also available.
• In order to strengthen mixes against new legal attack, such as compulsion to reveal keys, I have proposed the design of forward secure mixes. Using key updating techniques, even the intermediate nodes that have in the past processed the message cannot trace it back, provided they follow the protocols. A paper presenting these ideas has been presented at the NorSec2002 conference.

• Mike Bond and I just published a new technical report entitled "A pact with the Devil" (see Techical Report 666). We look at how viruses may give benefits to the owners of the computers they propagate on in conjunction to using threats and blackmail to entrench themselves.
• We have been implementing with Richard "Chaffinch", a system that provides confidentiality and plausible deniability using only authentication primitives. The paper describing it in detail can be found here [pdf,html].

• Some original sources relating the technical details of the latest Greek interception scandals were translated into English.
• In December 2001 I took part in the EU Cybercrime forum on the subject of the retention of traffic data, as part of the Internet Rights Europe initiative. My positions on the subject, and the other contributions, can be found here. Other sources of information about data retention are EPIC, FIPR, Statewatch
• My position on the issue of traffic data retention and its impact on civil society was presented at the first World Civil Society Forum, in Geneva. The position paper and the slides are available.
• I have caused a bit of fuss about the wild usage of RFid technology for managing the access control in WSIS (Geneva 2003). This work made us candidates for the Prix Voltaire of the French Big Brother awards 2004.

Talks

• 2005-12-01: Introducing Traffic Analysis: Attacks, Defences and Public Policy Issues... Invited Talk. Santa's Crypto Get-together. Prague, December 2005.
• 2005-10-15: The mixminion packet format, Invited talk, Dagshtul Workshop Anonymous Communication.
• 2005-09- : Abuse resistant DHT routing. ESORICS 2005, Milan.
• 2005-06- : Compulsion resistant anonymous communications. IH 2005, Barcelona.
• 2005-05-10: Low-cost Traffic Analysis of Tor. 2005 IEEE Symposium on Security and Privacy, Berkeley.
• 2004-12-28: Anonymous Communications, Chaos Communication Congress, Berlin
• 2004-11-08: An Introduction to Traffic Analysis UMass (Amherst, MA) and UMass (Lowell, MA).
• 2004-10-28: Minx: A Simple and Efficient Anonymous Packet Format WPES 2004 (Washington DC)
• 2004-07-17: An Introduction to Privacy Enhancing Technologies (PETs) Internet Society Geneva
• 2004-06-17: The Economics of Security Communications Innovation Institute launch event.
• 2004-05-29: The Anonymity of Continuous Time Mixes PET 2004 (Toronto).
• 2004-05-14: The Economics of Censorship Resistance WEIS 2004 (Minneapolis).
• 2004-02-17: Anonymous communications & Traffic analysis Security Seminar.
• 2003-12-14: RFid and WSIS WSIS 2003 (Geneva)
• 2003-09-24: What Future for Anonymity Research? COSIC Group (Leuven).
• 2003-05-28: The Statistical Disclosure Attack SEC 2003 (Athens).
• 2003-04-23: Two traffic analysis attacks COSIC Group (Leuven).
• 2003-03-26: Mix-networks with restricted routes PET 2003 (Dresden).
• 2002-11-08: Forward Secure Mixes NordSec 2002 (Karlstad)
• 2002-10-07: Chaffinch Information Hiding 2003.

Publications

• Yoni De Mulder, George Danezis, Lejla Batina and Bart Preneel. Identification via Location-Profiling in GSM Networks. Workshop on Privacy in the Electronic Society (WPES 2008), Alexandria, Virginia, USA.

• George Danezis and Paul Syverson. Bridging and Fingerprinting: Epistemic Attacks on Route Selection. Privacy Enhancing Technologies Symposium (PETS 2008), Leuven, Belgium.
• George Danezis and Len Sassaman. How to Bypass Two Anonymity Revocation Schemes. Privacy Enhancing Technologies Symposium (PETS 2008), Leuven, Belgium.
• George Danezis. Covert Communications Despite Traffic Data Retention. Cambridge Security Protocols Workshop (SPW 2008). Sidney Sussex College, Cambridge, UK.
• Daniel Cvrcek and George Danezis. Fighting the Good Internet War. Cambridge Security Protocols Workshop (SPW 2008). Sidney Sussex College, Cambridge, UK.
• Nikita Borisov, George Danezis, Prateek Mittal and Parisa Tabriz. Denial of Service or Denial of Security? How Attacks on Reliability can Compromise Anonymity. ACM CCS 2007.
• B. Preneel, C. Troncoso, G. Danezis, and E. Kosta. PriPAYD: Privacy Friendly Pay-As-You-Drive Insurance. In Workshop on Privacy in the Electronic Society 2007, ACM, 9 pages, 2007.
• C. Diaz, C. Troncoso, and G. Danezis. Does additional information always reduce anonymity?. In Workshop on Privacy in the Electronic Society 2007, ACM, 4 pages, 2007.
• G. Danezis, C. Diaz, S. Faust, E. Käsper, B. Preneel, and C. Troncoso. Efficient Negative Databases from Cryptographic Hash Functions, In Proceedings of the 10th Information Security Conference (ISC 2007), Lecture Notes in Computer Science LNCS, J. A. Garay (ed.), Springer-Verlag, 12 pages, 2007.
• George Danezis, Claudia Diaz and Carmela Troncoso. Two-sided Statistical Disclosure Attack. PET 2007, Ottawa, Canada.
• George Danezis and Ben Laurie. Private Yet Abuse Resistant Open Publishing. XVth Security Protocols Workshop. Brno.
• George Danezis and Claudia Diaz. Space-Efficient Private Search with Applications to Rateless Codes . Financial Cryptoraphy 2007.
• Dan Cvrcek, Marek Kumpost, Vashek Matyas and George Danezis. Study on the Price of Privacy. ACM WPES..
• Mike Bond and George Danezis. A Pact with the Devil. New Security Paradigms Workshop 2006, Dagstuhl, Germany.
• George Danezis and Richard Clayton. Route Fingerprinting in Anonymous Communications. 6th IEEE International Conference on Peer-to-Peer Computing, Cambridge 2006.
• George Danezis. Breaking Four Mix-related Schemes Based on Universal Re-encryption. Information Security Conference 2006.
• George Danezis, Bettina Wittneben. The Economics of Mass Surveillance and the Questionable Value of Anonymous Communications. WEIS 2006.
• Dan Cvrcek, Marek Kumpost, Vashek Matyas and George Danezis. The Value of Location Information: A European-Wide Study. Cambridge Security Protocols Workshop 2006.
• George Danezis, Chris Lesniewski-Laas, M. Frans Kaashoek and Ross Anderson. Sybil-resistant DHT routing. ESORICS 2005.
• George Danezis and Jolyon Clulow. Compulsion Resistant Anonymous Communications. 7th Information Hiding Workshop, Barcelona, Spain.
• George Danezis, Stephen Lewis and Ross Anderson. How Much is Location Privacy Worth?. Fourth Workshop on the Economics of Information Security (WEIS 2005). Harvard University, 2 - 3 June 2005.
• Steven J. Murdoch and George Danezis. Low-cost Traffic Analysis of Tor. 2005 IEEE Symposium on Security and Privacy, May 8-11, 2005, Oakland, California, USA.
• Mike Bond and George Danezis. The Dining Freemasons (Security Protocols for Secret Societies). Thirteenth International Workshop on Security Protocols, Cambridge, England -- 20-22 April 2005.
• George Danezis, Ross Anderson. The economics of resisting censorship, Security & Privacy Magazine, IEEE, Volume: 3, Issue: 1, Year: Jan.-Feb. 2005, Page(s): 45- 50.
• George Danezis and Ben Laurie. Minx: A Simple and Efficient Anonymous Packet Format WPES 2004, Washington DC, October 2004.
• Rainer Bohme, George Danezis, Claudia Diaz, Stefan Kopsell, and Andreas Pfitzmann . Mix Cascades vs. Peer-to-Peer: Is One Concept Superior?, Privacy Enhancing Technologies Workshop 2004. Toronto.
• George Danezis. The Traffic Analysis of Continuous-Time Mixes. Privacy Enhancing Technologies Workshop 2004. Toronto. 
• George Danezis, Ross Anderson. The Economics of Censorship Resistance. Worshop on Economics and Information Security.
• George Danezis, Andrei Serjantov. Statistical Disclosure or Intersection Attacks on Anonymity Systems, Information Hiding 2004.
• George Danezis, Len Sassaman, Heartbeat Traffic to Counter (n-1) Attacks, WPES'03.
• George Danezis: The Statistical Disclosure Attack. Sec2003.
• George Danezis, Roger Dingledine, Nick Mathewson: Mixminion: Design of a Type III Anonymous Remailer. IEEE Security & Privacy 2003.
• George Danezis: Mix-networks with Restricted Routes PET 2003.
• George Danezis: Forward Secure Mixes. NORDSEC 2002.
• Richard Clayton, George Danezis: Chaffinch: Confidentiality in the Face of Legal Threats. Information Hiding 2002: 70-86. 
• Andrei Serjantov, George Danezis: Towards an Information Theoretic Metric for Anonymity. Privacy Enhancing Technologies 2002. Award at PET2003.
• Richard Clayton, George Danezis, Markus G. Kuhn: Real World Patterns of Failure in Anonymity Systems. Information Hiding 2001: 230-244.
• George Danezis: An Anonymous Auction Protocol Using "Money Escrow" (Transcript of Discussion). Security Protocols Workshop 2000: 223-233

• George Danezis: Introducing Traffic Analysis: Attacks, Defences and Public Policy Issues... (Invited Talk). Santa's Crypto Get-together. Prague, December 2005. Also at 23C3, Berlin.
• George Danezis: Traffic Analysis of the HTTP Protocol over TLS.
• Mike Bond, George Danezis. A pact with the Devil. Technical report UCAM-CL-TR-666, University of Cambridge, Computer Laboratory, June 2006
• George Danezis and Richard Clayton. Introducing Traffic Analysis. Chapter in Digital privacy. Auerbach Publications, ISBN: 9781420052176.
• George Danezis and Claudia Diaz. A survey of anonymous communication channels. Microsoft Research Technical Report (MSR-TR-2008-35). January 2008.

Ph.D

To get where i am today I had to do a Ph.D. at the Computer Laboratory of the University of Cambridge. My supervisor was Prof. Ross J. Anderson, in the security group. My doctoral thesis entitled Better Anonymous Communications and the associated technical report Designing and Attacking Anonymous Communication Systems (UCAM-CL-TR-594) are available.

Links

How you can contact me

Phone:   +44 (1223) 479812 X3812 
Email:   gdane at microsoft com

Cryptography, Security and Algorithms Group's home page.