On Web User Tracking: How Third-Party Http Requests Track Users' Browsing Patterns for Personalised Advertising

On today's Web, users trade access to their private data for content and services. Advertising sustains the business model of many websites and applications. Efficient and successful advertising relies on predicting users' actions and tastes to suggest a range of products to buy. It follows that, while surfing the Web users leave traces regarding their identity in the form of activity patterns and unstructured data. We analyse how advertising networks build user footprints and how the suggested advertising reacts to changes in the user behaviour.Comment: arXiv admin note: substantial text overlap with arXiv:1605.0653

Potential mass surveillance and privacy violations in proximity-based social applications

Proximity-based social applications let users interact with people that are currently close to them, by revealing some information about their preferences and whereabouts. This information is acquired through passive geo-localisation and used to build a sense of serendipitous discovery of people, places and interests. Unfortunately, while this class of applications opens different interactions possibilities for people in urban settings, obtaining access to certain identity information could lead a possible privacy attacker to identify and follow a user in their movements in a specific period of time. The same information shared through the platform could also help an attacker to link the victim's online profiles to physical identities. We analyse a set of popular dating application that shares users relative distances within a certain radius and show how, by using the information shared on these platforms, it is possible to formalise a multilateration attack, able to identify the user actual position. The same attack can also be used to follow a user in all their movements within a certain period of time, therefore identifying their habits and Points of Interest across the city. Furthermore we introduce a social attack which uses common Facebook likes to profile a person and finally identify their real identity

On the anonymity risk of time-varying user profiles.

Websites and applications use personalisation services to profile their users, collect their patterns and activities and eventually use this data to provide tailored suggestions. User preferences and social interactions are therefore aggregated and analysed. Every time a user publishes a new post or creates a link with another entity, either another user, or some online resource, new information is added to the user profile. Exposing private data does not only reveal information about single users’ preferences, increasing their privacy risk, but can expose more about their network that single actors intended. This mechanism is self-evident in social networks where users receive suggestions based on their friends’ activities. We propose an information-theoretic approach to measure the differential update of the anonymity risk of time-varying user profiles. This expresses how privacy is affected when new content is posted and how much third-party services get to know about the users when a new activity is shared. We use actual Facebook data to show how our model can be applied to a real-world scenario.Peer ReviewedPostprint (published version

De la notion au concept: Les images de l'autre dans le journal EUZKADI (1931-1937)

International audienceAnalyse du contenu racial et religieux du journal porte-parole du Parti Nationaliste Basque entre 1930 et 1937. Construction d'un imaginaire de la négation de l'autre. La religion comme légitimation de la race

On web user tracking of browsing patterns for personalised advertising

This is an Accepted Manuscript of an article published by Taylor & Francis in International Journal of Parallel, Emergent and Distributed Systems on 19/02/2017, available online: http://www.tandfonline.com/doi/abs/10.1080/17445760.2017.1282480On today’s Web, users trade access to their private data for content and services. App and service providers want to know everything they can about their users, in order to improve their product experience. Also, advertising sustains the business model of many websites and applications. Efficient and successful advertising relies on predicting users’ actions and tastes to suggest a range of products to buy. Both service providers and advertisers try to track users’ behaviour across their product network. For application providers this means tracking users’ actions within their platform. For third-party services following users, means being able to track them across different websites and applications. It is well known how, while surfing the Web, users leave traces regarding their identity in the form of activity patterns and unstructured data. These data constitute what is called the user’s online footprint. We analyse how advertising networks build and collect users footprints and how the suggested advertising reacts to changes in the user behaviour.Peer ReviewedPostprint (author's final draft

El arte de la reversibilidad en cuatro relatos de familiares de desaparecidos

En este trabajo me propongo examinar algunos repertorios artísticos de los relatos de los familiares de desaparecidos de la última dictadura militar en Argentina con el fin de indagar en los sentidos de la remediación como estrategia estético-ideológica. Propondré una lectura que toma en consideración el concepto de remediación, en conexión con lo que nombraré el arte de la reversibilidad. En la lectura de Los rubios (2003) de Albertina Carri, Ausencias (2006-2007) de Gustavo Germano, Diario de una princesa montonera (2010-2012) de Mariana Eva Pérez y, finalmente, Arqueología de la ausencia (1999-2001) de Lucila Quieto destacaré cuatro estrategias narrativas –el palimpsesto, los paralelos, los collages y las ventanas– todas las cuales de distintas maneras se articulan según la doble lógica de la remediación planteada por Bolter y Grusin (1999)

Anàlisis de les dades topogràfiques d'una mostra de pacients del CUV

OBJECTIU: Els objectius principals del treball són: determinar si l’astigmatisme depèn de l’edat o ve del sexe, observar com pacients amb queratocon no segueixen cap patró de normalitat, i per últim obtenir l’excentricitat mitjana dels pacients amb còrnies normals. MATERIAL I MÈTODES: Dos-cents pacients escollits l’atzar de la base de dades del Topògraf (Pentacam) del CUV i, un cop separats en còrnies normals o bé amb ectàsia, es reparteixen en 4 grups d’edat: 0-18, 19-40, 41-65 i >65 anys, sent important el fet que no es va excloure cap pacient. Analitzant les topografies de cada pacient i amb la seva graduació extreta de la base de dades de l’Optiplus n’extraurem els resultats i les conclusions. RESULTATS: Entre 0 i 40 anys, predomina: l’astigmatisme mig, regular, compost i directe. De 41- 65 anys predomina: l’astigmatisme mig, regular, mixt i directe. Per >65 anys, l’astigmatisme predominant és: baix, regular, compost i invers. Per les dones, predomina l’astigmatisme mig; regular; compost en edats de 0-40, mixt de 41 a majors de 65; directe, fins als 65 anys, i >65 l’oblic. En homes, predomina l’astigmatisme mig, excepte en majors de 65 anys que canvia a baix; regular; compost dels 0-40 anys, mentre que de 41-65 anys hi predomina el mixt i per sobre els 65anys s’observa com destaca el compost; directe menys per sobre els 65 anys que es torna invers. Els pacients amb queratocon segueixen un patró comú, el qual predomina per sobre d’un 70% l’astigmatisme del tipus irregular. L’excentricitat corneal mitja de l’estudi, és: 0,449. CONCLUSIONS: No s’observen diferències en el tipus d’astigmatisme entre homes i dones. Ara bé, en persones de més de 65 anys els resultats varien respecte a persones d’entre 0-65 anys. Per tant, podem concloure, que l’edat és un factor influent en el grau d’astigmatisme però no el sexe. També podem assegurar que l’astigmatisme dels pacients que presenten ectàsies corneals, no segueix cap patró de normalitat. A més, el resultat mitjà de l’excentricitat corneal de l’estudi es situa dintre dels valors de normalitat

On the Measurement of Privacy as an Attacker's Estimation Error

A wide variety of privacy metrics have been proposed in the literature to evaluate the level of protection offered by privacy enhancing-technologies. Most of these metrics are specific to concrete systems and adversarial models, and are difficult to generalize or translate to other contexts. Furthermore, a better understanding of the relationships between the different privacy metrics is needed to enable more grounded and systematic approach to measuring privacy, as well as to assist systems designers in selecting the most appropriate metric for a given application. In this work we propose a theoretical framework for privacy-preserving systems, endowed with a general definition of privacy in terms of the estimation error incurred by an attacker who aims to disclose the private information that the system is designed to conceal. We show that our framework permits interpreting and comparing a number of well-known metrics under a common perspective. The arguments behind these interpretations are based on fundamental results related to the theories of information, probability and Bayes decision.Comment: This paper has 18 pages and 17 figure

Capital social como fuente de ventaja competitiva en la obra civil

En el trabajo se investiga si una ventaja competitiva puede tener su fuente en las relaciones corporativas, ya que éstas tienen mecanismos de aislamiento superiores. Asimismo se profundizará en cómo las relaciones interorganizativas son capaces de generar capital social, y éste a su vez es capaz de constituir una fuente de ventaja competitiva sostenible