There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

2 1 The innovative transport systems and the CityMobil project 10 1.1 The research questions 10 2 The state of art in the field of automatic transport systems 12 2.1 Case studies and demand studies for innovative transport systems 12 3 The design and implementation of surveys 14 3.1 Definition of experimental design 14 3.2 Questionnaire design and delivery 16 3.3 First analyses on the collected sample 18 4 Calibration of Logit Multionomial demand models 21 4.1 Methodology 21 4.2 Calibration of the “full” model. 22 4.3 Calibration of the “final” model 24 4.4 The demand analysis through the final Multinomial Logit model 25 5 The analysis of interaction between the demand and socioeconomic attributes 31 5.1 Methodology 31 5.2 Application of Mixed Logit models to the demand 31 5.3 Analysis of the interactions between demand and socioeconomic attributes through Mixed Logit models 32 5.4 Mixed Logit model and interaction between age and the demand for the CTS 38 5.5 Demand analysis with Mixed Logit model 39 6 Final analyses and conclusions 45 6.1 Comparison between the results of the analyses 45 6.2 Conclusions 48 6.3 Answers to the research questions and future developments 52

The European commission

We present Tor, a circuit-based low-latency anonymous communication service. This second-generation Onion Routing system addresses limitations in the original design by adding perfect forward secrecy, congestion control, directory servers, integrity checking, configurable exit policies, and a practical design for location-hidden services via rendezvous points. Tor works on the real-world Internet, requires no special privileges or kernel modifications, requires little synchronization or coordination between nodes, and provides a reasonable tradeoff between anonymity, usability, and efficiency. We briefly describe our experiences with an international network of more than 30 nodes. We close with a list of open problems in anonymous communication.

/pdf/tor-the-second-generation-onion-router-2qfrg0ppqb.pdf

Tor: the second-generation onion router

Social Network Analysis

National Institute of Standards and Technology における超伝導研究及び生活

In this paper we look at the information an attacker can extract using a statistical disclosure attack. We provide analytical results about the anonymity of users when they repeatedly send messages through a threshold mix following the model of Kesdogan, Agrawal and Penz [7] and through a pool mix. We then present a statistical disclosure attack that can be used to attack models of anonymous communication networks based on pool mixes. Careful approximations make the attack computationally efficient. Such models are potentially better suited to derive results that could apply to the security of real anonymous communication networks.

Statistical disclosure or intersection attacks on anonymity systems

We design and prototype protocols for processing smart-meter readings while preserving user privacy We provide support for computing non-linear functions on encrypted readings, implemented by adapting to our setting efficient secret-sharing-based secure multi-party computation techniques Meter readings are jointly processed by a (public) storage service and a few independent authorities, each owning an additive share of the readings For non-linear processing, these parties consume pre-shared materials, produced by an off-line trusted third party This party never processes private readings; it may be implemented using trusted hardware or somewhat homomorphic encryption The protocol involves minimal, off-line support from the meters---a few keyed hash computations and no communication overhead

/pdf/smart-meter-aggregation-via-secret-sharing-4nj5y5dgah.pdf

Smart meter aggregation via secret-sharing

Pri-PAYD: Privacy Friendly Payas- you-drive Insurance

We consider the eect attackers who disrupt anonymous communications have on the security of traditional high- and low-latency anonymous communication systems, as well as on the Hydra-Onion and Cashmere systems that aim to oer reliable mixing, and Salsa, a peer-to-peer anonymous communication network. We show that denial of service (DoS) lowers anonymity as messages need to get retransmitted to be delivered, presenting more opportunities for attack. We uncover a fundamental limit on the security of mix networks, showing that they cannot tolerate a majority of nodes being malicious. Cashmere, Hydra-Onion, and Salsa security is also badly aected by DoS attackers. Our results are backed by probabilistic modeling and extensive simulations and are of direct applicability to deployed anonymity systems.

/pdf/denial-of-service-or-denial-of-security-how-attacks-on-32glw3sjhk.pdf

George Danezis

Papers

Statistical disclosure or intersection attacks on anonymity systems

Smart meter aggregation via secret-sharing

Statistical disclosure or intersection attacks on anonymity systems

Pri-PAYD: Privacy Friendly Payas- you-drive Insurance

Denial of Service or Denial of Security? How Attacks on Reliability can Compromise Anonymity