Un peu de recherche…

2 LIRIS/DCS/DRIM

3 Nostalgia: an overview of the past 10 years Some contributions to the management of data in grids Some contributions to Pervasive/Ubiquitous Systems… and other distributed systems (incl. security and privacy)

Some contributions to the management of data in grids

5 Computing/Data Grid (1) “ coordinated resource sharing and problem solving in dynamic, multi-institutional virtual organisations” (I. Foster)

6 Computing/Data Grids (2) Large scale Unpredictability, dynamicity Security, privacy Resource heterogeneity and usage diversity Decentralized administration

7 Monitoring de grilles Where to place instances (replicas) of a service? What resource (set of resources) (what service) use? Condition: monitor the grid state: CPU load, network load… Design and implementation of a grid service that processes high- level information requests that represent the user’s specific needs in terms of resources

8 NDS : Network Distance Service

9 Grid access control: Sygn Mechanisms for delegation of rights File group operations Permission = Authorization Certificate (AC) : – Issuer – Owner – Capability (access control object + authorized action) – Validity – Signature

10 Encrypted Storage for Data Grids: Crypstore

11 Management of a Cooperative Cache in Grids cache organization GRID data organization data Collective Coordinator Monitoring operations data description processed requests transfers replacements used storage resource Etc. Management operations Set replacement method Set default time to live Set cache group Set cache coordinator Set collective work mode Etc.

12 Data Integration

13 Some Contributions to Pervasive/Ubiquitous Systems… and Other Distributed Systems (incl. Security and Privacy)

14 Pervasive, Ubiquitous, Mobile, Ambient, Ad Hoc ? Introduction to pervasive systems Hansel and Gretel are lost in the forest of PC definitions… Basics (1) – Mobility (wireless) / autonomy – User (or device)-centric – Context-awareness (user prefs, environment) Basics (2) – Lightweight appliances and devices – Proactivity  Make the digital world/information omnipresent but invisible

15 PerSE Adaptation context Models Context-Awareness Proactivity Service Composition

16 Architecture of a PerSE Base

17 PerSE Layers

18 Context Modeling and Context-Aware Pervasive Applications Context = ? User/Application centric context Context-aware application platform

19 Access Control of Mobile Users Chains of trust certificates: if A trusts B and B trusts C then A trusts C… to some level Multi-layered adaptive certificates Trust computing and reputation

20 Privacy-Preserving Reputation Systems Reputation: aggregation of feedbacks Query agent, target agent, source agents Goal: computing the reputation while not revealing the individual feedbacks Approach: use trust relations in the reputation protocol for enforce the privacy + “cut” feedbacks into pieces (“shares”) + use cryptographic tools

21 Authentication and Trust in Pervasive Systems

22 Mobile Requests Information exchange between mobile peers (MANETs, VANETs) Trajectory aware geocast request routing Construction for each query of an ad hoc overlay of the peers that may participate to the delivery of the requested data

23 Data Replication in Small Worlds Server Original content

24 Replication in Ad Hoc Networks Issues: instability, dynamicity, faults/disconnections Basic idea: adapt the replication heuristics to the actual usage of the data, e.g.: –Data highly accessed => replicate –Rare data and planned disconnection => replicate –Overloaded peer => replicate most accessed data –Etc. Pre-requisite: access logging + exchange of access data Assumption: no central coordination – local decisions Question : can local decisions lead to an acceptable (good ?) situation ?

25 Interface Adaptation and Context-Aware Browsing of a Patient Medical Record

26 Multimedia Content Adaptation + Adaptation of the interface wrt the end-user device Ongoing : Content Adaptation in MANETs

27 Semantic Protection of Multimedia Data Multimedia => access control is not a binary decision Access control content adaptation Coherence/Consistence of an adaptation Legality of an adaptation => Access control = semantic adaptation decision

28 Semantic Clustering of Multimedia Queries: From Query Logging to Database Content and User Profile Discovery Large number of data stores disseminated Lack of indexes Issues : –What are the pertinent/interesting data ? –What are the users interest ? –How to process a query ? Logging of the users’ queries + clustering + communication of clustering info => identification of the community of users’ interests Logging of a the queries issued by a specific user + matching to the community clustering => identification of the user’s profile Usage: query optimization, data store management, recommendation, social computing, etc.

29 BAR-Tolerant Publish-subscribe P2P Systems Collaboration Modeling and Enhancing: a Game Theoretical Approach Byzantine-Altruistic-Rational Publish an information; disseminate the information to subscribers Systems benchmarking tool GT modeling of collaborative systems

30 Ambient Social Networks and Message Routing in DTN Ambient social networks Delay Tolerant Networks (DTN) and Opportunistic Networks Mobility traces/model Message routing

31 Ongoing work: User-centric Ubiquitous Multi-Scale Digital Ecosystems Information retrieval in P2P systems Privacy-preserving personal data mining (EEXCESS project) Privacy-preserving recommendation systems (EEXCESS project) Privacy-preserving multimedia data routing Open data and user-as-sensor based ambient social services Game-theory-based cooperation modeling and enhancing in distributed systems Trust and reputation in B2B networks (AttestationLegale) Information protection in clouds Social-aware event driven architectures Mobile Crowd Sourcing, Sensing, and Computing: Intelligence, Aggregation, Resilience (if opportunity) Adaptive and information value-based protection of business processes (if opportunity) Security of the social web of things ???

32 Faites de la recherche (au moins un peu) !