Alexandre Viejo

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Web search engines (e.g. Google, Yahoo, Microsoft Live Search...) are widely used to find certain data among a huge amount of information in a minimal amount of time. However, these useful tools also pose a privacy threat to the users: web search engines profile their users by storing and analyzing past searches submitted by them. To address this privacy(More)
Vehicular ad hoc networks (VANETs) allow vehicleto-vehicle communication and, in particular, vehicle-generated announcements. Provided that the trustworthiness of such announcements can be guaranteed, they can greatly increase the safety of driving. A new system for vehicle-generated announcements is presented that is secure against external and internal(More)
The Internet is one of the most important sources of knowledge in the present time. It offers a huge volume of information which grows dramatically every day. Web search engines (e.g. Google, Yahoo...) are widely used to find specific data among that information. However, these useful tools also represent a privacy threat for the users: the web search(More)
Web search engines (WSEs) are tools that allow users to retrieve specific contents from the Internet. However, during this process, users’ queries and related information (e.g., query time, browser type, etc.) are stored and analyzed in the WSE database. The stored logs may contain sensitive information (e.g., health issues, location, religion, etc.) and(More)
The advent of new information sharing technologies has led society to a scenario where thousands of textual documents are publicly published every day. The existence of confidential information in many of these documents motivates the use of measures to hide sensitive data before being published, which is precisely the goal of document sanitization. Even(More)
Web search engines are tools employed to find specific information in the Internet. However, they also represent a threat for the privacy of their users. This happens because the web search engines store and analyze the personal information that the users reveal in their queries. In order to avoid this privacy threat, it is necessary to provide mechanisms(More)
Web search engines (WSEs) are basic tools for finding and accessing data in the Internet. However, they also put the privacy of their users at risk. This happens because users frequently reveal private information in their queries. WSEs gather this personal data and build user profiles which are used to provide personalized search (PS). PS improves the(More)
Enabling private relationships in social networks is an important issue recently raised in the literature. We describe in this paper a new protocol which offers private relationships allowing resource access through indirect relationships without requiring a mediating trusted third party (although an optimistic trusted third party is used which only acts in(More)
Whenever a document containing sensitive information needs to be made public, privacy-preserving measures should be implemented. Document sanitization aims at detecting sensitive pieces of information in text, which are removed or hidden prior publication. Even though methods detecting sensitive structured information like e-mails, dates or social security(More)
Web search engines (WSE) have become an essential tool for searching information on the Internet. In order to provide personalized search results for the users, WSEs store all the queries which have been submitted by the users and the search results which they have selected. The AOL scandal in 2006 proved that this information contains personally(More)