Input online review data and related bias in recommender systems

in Decision Support Systems (2012), 53(3), 418-424

A majority of extant literature on recommender systems assume the input data as a given to generate recommendations. Both implicit and/or explicit data are used as input in these systems. The existence of ... [more ▼]

A majority of extant literature on recommender systems assume the input data as a given to generate recommendations. Both implicit and/or explicit data are used as input in these systems. The existence of various challenges in using such input data including those associated with strategic source manipulations, sparse matrix, state data, among others, are sometimes acknowledged. While such input data are also known to be rife with various forms of bias, to our knowledge no explicit attempt is made to correct or compensate for them in recommender systems. We consider a specific type of bias that is introduced in online product reviews due to the sequence in which these reviews are written. We model several scenarios in this context and study their properties. [less ▲]

Operational semantics and verification of security protocols

Book published by Springer-Verlag (2012)

Security protocols are widely used to ensure secure communications over insecure networks, such as the internet or airwaves. These protocols use strong cryptography to prevent intruders from reading or ... [more ▼]

Security protocols are widely used to ensure secure communications over insecure networks, such as the internet or airwaves. These protocols use strong cryptography to prevent intruders from reading or modifying the messages. However, using cryptography is not enough to ensure their correctness. Combined with their typical small size, which suggests that one could easily assess their correctness, this often results in incorrectly designed protocols. The authors present a methodology for formally describing security protocols and their environment. This methodology includes a model for describing protocols, their execution model, and the intruder model. The models are extended with a number of well-defined security properties, which capture the notions of correct protocols, and secrecy of data. The methodology can be used to prove that protocols satisfy these properties. Based on the model they have developed a tool set called Scyther that can automatically find attacks on security protocols or prove their correctness. In case studies they show the application of the methodology as well as the effectiveness of the analysis tool. The methodology’s strong mathematical basis, the strong separation of concerns in the model, and the accompanying tool set make it ideally suited both for researchers and graduate students of information security or formal methods and for advanced professionals designing critical security protocols. [less ▲]

Comparative analysis of clustering protocols with probabilistic model checking

in Proc. 6th International Symposium on Theoretical Aspects of Software Engineering (2012)

Implementation and Validation of a Localisation Assurance Service Provider

in Proc. 6th ESA Workshop on Satellite Navigation Technologies (2012)

Existing Global Navigation Satellite Systems offer no authentication to the open service signals and so stand-alone receivers are vulnerable to meaconing and spoofing attacks. These attacks interfere with ... [more ▼]

Existing Global Navigation Satellite Systems offer no authentication to the open service signals and so stand-alone receivers are vulnerable to meaconing and spoofing attacks. These attacks interfere with the integrity and authenticity of satellite signals: they can delay signals, or re-broadcast signals. Positioning is thus compromised and location-based services are at risk.This paper describes a solution to mitigate this risk. It is a trusted third-party Localisation Assurance service that informs location-based services providers up to which level a location claimed by client can be trusted. It runs several tests over the localisation data of client receivers and certifies the level of assurance of locations. An assurance level expresses the amount of trust the third-party has that a receiver's location is calculated from integral and authentic satellite signals. [less ▲]

Probabilistic model checking of the PDGF signaling pathway

in Transactions on Computational Systems Biology (2012), XIV

Location-Based Services: Privacy, Security and Assurance

in Digital Enlightenment Yearbook 2012 (2012)

mCarve: Carving attributed dump sets

in Abstract book of 20th USENIX Security Symposium (2011)

A study of the PDGF signaling pathway with PRISM

in Proceedings of the 3rd Workshop on Computational Models for Cell Processes (2011), EPTCS 67

Selective location blinding using hash chains

in Proc. 19th International Workshop on Security Protocols (2011)

Fair Exchange

in Rosenberg, G. (Ed.) Handbook of Financial Cryptography and Security (2010)