Un peu de recherche…

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LIRIS/DCS/DRIM

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Nostalgia: an overview of the past10 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

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Computing/Data Grid (1)

“coordinated resource sharing and problem solving in dynamic, multi-institutional virtual organisations” (I. Foster)

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Computing/Data Grids (2)

• Large scale

• Unpredictability, dynamicity

• Security, privacy

• Resource heterogeneity and usage diversity

• Decentralized administration

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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

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NDS : Network Distance Service

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Grid access control: Sygn

Mechanisms for delegation of rightsFile group operations

• Permission = Authorization Certificate (AC) :– Issuer – Owner – Capability (access

control object + authorized action)

– Validity– Signature

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Encrypted Storage for Data Grids: Crypstore

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Management of a Cooperative Cache in Grids

cachecache

cache

cache

organization

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.

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Data Integration

Basede

correspondances

DS

Base de

correspondances

DS

DS DS

DS

Registre de services

de données

Registre deservices

de données

Médiateurnégociateur

Médiateurnégociateur

DS : Data Service(service de données)

Correspondancenégociée

Zones de négociationimbriquées

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Some Contributions to Pervasive/Ubiquitous Systems… and

Other Distributed Systems (incl. Security and Privacy)

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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

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PerSE

Adaptation

context

Models

•Context-Awareness•Proactivity•Service Composition

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Architecture of a PerSE Base

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PerSE Layers

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Context Modeling and Context-Aware Pervasive Applications

• Context = ?

• User/Application centric context

• Context-aware application platform

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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

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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

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Authentication and Trust in Pervasive Systems

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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

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Data Replication in Small Worlds

ServerOriginal content

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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 ?

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Interface Adaptation and Context-Aware Browsing

of a Patient Medical Record

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Multimedia Content Adaptation

+ Adaptation of the interface wrt the end-user deviceOngoing : Content Adaptation in MANETs

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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

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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.

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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

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Ambient Social Networks andMessage Routing in DTN

• Ambient social networks

• Delay Tolerant Networks (DTN) and Opportunistic Networks

• Mobility traces/model

• Message routing

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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• ???

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Faites de la recherche

(au moins un peu)

!