Multiparty Routing: Secure Routing for Mixnets
Event details
| Date | 29.08.2018 |
| Hour | 10:15 |
| Speaker | Dr. Fatemeh Shirazi, KU Leuven, Belgium |
| Location | |
| Category | Conferences - Seminars |
Abstract
In mix networks, communication anonymity is achieved by relaying messages through multiple routers called mixes, where each mix shuffles messages independently. Mix networks were originally set up as fixed sequences of mixes, called cascades. Later, more flexible configurations were proposed, such as free routes, where routes are not fixed and can be any sequence of mixes. The concrete sequence of mixes followed by a message can be chosen by the initiator of the communication, as is in source routing, or decided locally by each relay that receives the message, as is in hop-by-hop routing. In this paper we propose Multiparty Routing, an alternative routing protocol for anonymous communication systems that overcomes some of the disadvantages of existing routing schemes. In particular, multiparty routing substantially reduces the bandwidth overhead for clients compared to source routing, while providing much stronger anonymity properties towards network adversaries than hop-by-hop routing. Moreover, our protocol guarantees routing integrity and verifiability, by requiring that mixes prove the correctness of shuffling and routing. Our system further provides good load balancing properties as well as resilience against mix failure or DoS attacks. Lastly, we show that our system is secure against a powerful active adversary and implement a prototype to demonstrate its practicality.
Biography
Dr. Fatemeh Shirazi obtained her PhD in the COSIC group at KU Leuven. Her PhD research focuses on anonymous communication systems. Before coming to KU Leuven, she was a research assistant and teaching assistant under the supervision of Prof. Johannes Buchmann at TU Darmstadt, where she was also part of the acatech Internet Privacy project. She obtained her M.Sc. in Computer Science from Saarland University, where she worked for two years as a part-time student assistant at DFKI (German Research Center for Artificial Intelligence) in the Secure Systems group led by Dr. Werner Stephan.
In mix networks, communication anonymity is achieved by relaying messages through multiple routers called mixes, where each mix shuffles messages independently. Mix networks were originally set up as fixed sequences of mixes, called cascades. Later, more flexible configurations were proposed, such as free routes, where routes are not fixed and can be any sequence of mixes. The concrete sequence of mixes followed by a message can be chosen by the initiator of the communication, as is in source routing, or decided locally by each relay that receives the message, as is in hop-by-hop routing. In this paper we propose Multiparty Routing, an alternative routing protocol for anonymous communication systems that overcomes some of the disadvantages of existing routing schemes. In particular, multiparty routing substantially reduces the bandwidth overhead for clients compared to source routing, while providing much stronger anonymity properties towards network adversaries than hop-by-hop routing. Moreover, our protocol guarantees routing integrity and verifiability, by requiring that mixes prove the correctness of shuffling and routing. Our system further provides good load balancing properties as well as resilience against mix failure or DoS attacks. Lastly, we show that our system is secure against a powerful active adversary and implement a prototype to demonstrate its practicality.
Biography
Dr. Fatemeh Shirazi obtained her PhD in the COSIC group at KU Leuven. Her PhD research focuses on anonymous communication systems. Before coming to KU Leuven, she was a research assistant and teaching assistant under the supervision of Prof. Johannes Buchmann at TU Darmstadt, where she was also part of the acatech Internet Privacy project. She obtained her M.Sc. in Computer Science from Saarland University, where she worked for two years as a part-time student assistant at DFKI (German Research Center for Artificial Intelligence) in the Secure Systems group led by Dr. Werner Stephan.
Practical information
- General public
- Free
- This event is internal
Organizer
- Professor Bryan Ford
Contact
- Dr. Philpp Jovanovic