Papers

• Trust without Truth Michel Deriaz. In IFIP International Federation for Information Processing, Volume 238, Trust Management, eds. Etalle, s., Marsch, S., (Boston: Springer), pp. 31-45, Canada, 2007.
  Abstract. Can we trust without any reliable truth information? Most trust architectures work in a similar way: a trustor makes some observations, rates the trustee, and makes recommendations to his friends. When he faces a new case, he checks his trust table and uses recommendations given by trustworthy friends to decide whether he will undertake a given action. But what if the observations that are used to update the trust tables are wrong? How to deal with what we call the "uncertainty of the truth"? This paper presents how people that publish and remove virtual tags are able to create trust relations between them. A simulator as well as a concrete and widely deployed application have been used to validate our model. We observed good and encouraging results in general, but also some weaknesses, brought out through specific scenarios.
  
  
• Trust and Security in Spatial Messaging: FoxyTag, the Speed Camera Case Study Michel Deriaz and Jean-Marc Seigneur. In Proceedings of the 3rd International Conference on Privacy, Security and Trust, ACM, 2006.
  Abstract. Current speed cameras alerting systems heavily rely on humans to check the trustworthiness of information sent by their users. Hence, these systems are often either expensive or suffer from drawbacks, such as incomplete information, for example, concerning mobile speed cameras. We propose an application called FoxyTag to address most of the previous issues by using a computational trust engine instead of human checks. FoxyTag lets any driver equipped with a Java/GPSenabled mobile phone post a virtual tag about a speed camera to notify other equipped drivers who can confirm or deny the (short-lived) presence of the (mobile) camera. The novel aspect of our trust engine is that it must be location and time aware to automatically compute the trustworthiness of the given tag. We have validated FoxyTag both in real-life settings and with a simulator for large-scale scenarios. The validation showed that our novel time-patterned trust metrics are appropriate.
  
  

• Towards Trustworthy Spatial Messaging Michel Deriaz and Jean-Marc Seigneur. In Proceedings of the Second International Workshop on Security and Trust Management, ERCIM, ENTCS, 2006.
  Abstract. Spatial messaging is a term that defines the virtual publication of data in physical places. Generally, anyone in the neighborhood of such a publication point gets the message. Frameworks allowing the users to publish freely spatial messages already exist. However, the experiences realized with volunteers showed that there is only little interest in posting such notes. To our view, the main reason is that there are currently no trust and security mechanisms that inform about the trustworthiness of the messages, thus preventing any serious application. Filling this gap will promote the success of spatial messaging and the growing success of localization and mobile techniques will provide a good support for this concept. This paper describes the spatial messaging services that we are in the process to deploy with our new spatial messaging framework, which includes trust and security mechanisms.
  
  

• A Social Semantic Infrastructure for Decentralised Systems Based on Specification-Carrying Code and Trust Giovanna Di Marzo Serugendo, Michel Deriaz. In Proceedings of the Socially-Inspired Computing Workshop. pp. 143-152. D. Hales and B. Edmonds (Eds). Invited paper. 2005.
  Abstract. Decentralised systems made of autonomous devices and software are gaining more and more interest. These autonomous elements usually do not know each other in advance and act without any central control. They thus form a society of devices and software, and as such need: basic interaction mechanisms for understanding each other, and a social infrastructure supporting interactions taking place in an uncertain environment. In an effort to go beyond pre-established communication schema and to cope with uncertainty, this paper proposes an interaction mechanism based exclusively: on semantic information expressed using specifications, and on a social infrastructure relying on trust and reputation.
  
  

• Specification-Carrying Code for Self-Managed Systems Giovanna Di Marzo Serugendo, Michel Deriaz. In IFIP/IEEE International Workshop on Self-Managed Systems and Services. 2005.
  Abstract. This paper proposes the notion of Specification-Carrying Code as an interaction mechanism for self-assembly of autonomous decentralised software components. Each autonomous software entity incorporates more information than its operational behaviour, and publishes more data than its signature. The idea is to provide separately, for each entity, a functional part implementing its behaviour - the traditional program code; and an abstract description of the entity's functional behaviour and necessary parameters - a semantic behavioural description under the form of a formal specification. Interactions are exclusively based on the specifications and occur among entities with corresponding specifications. In the case of autonomic computing systems, in addition to functional aspects, the specification may carry a semantic description of non-functional information related to self-management. This paper presents the principles of the Specification-Carrying Code paradigm, the associated Service-Oriented Architecture, and it explains how self-managed systems can benefit from this paradigm.
  
  

Technical reports

• Trusting virtual tags Michel Deriaz. ASG technical report 07. 2007.
  Abstract. Spatial messaging, or the fact of publishing virtual tags, is clearly not a new concept. In the GPS world, these tags are materialized through POIs (Point Of Interest) and they consist more or less in geo-referenced information. They are often classified in different categories. A typical use is to show on a map all the neighboring POIs of a certain category. But the only solution to trust the information is to get them from a reliable source. This paper presents a first approach to a generic way of presenting these virtual tags, and how to add trust information to them. Every user is therefore able to create virtual tags and the trust engine is responsible to return to a specific user only the ones that he is interested in.
  
  

• Location Based Services for Traffic Management Lemonia Ragia and Michel Deriaz. ASG technical report 07. 2007.
  Abstract. Spatial data are used for location based services and to support traffic management systems. Data are gathered, saved and managed in a central database where, in principal, every user can access them putting data in a temporary database and then integrate them to a central. The proposed system uses a connection between database and trust engines in order to provide transparency. Security is an important aspect in our system to give confidence to the users to use their online services. We present an architecture for the implementation. The implemented system has been used in a small scenario for traffic information in a city center.
  
  

• FoxyTag Michel Deriaz and Jean-Marc Seigneur. ASG technical report 06. 2006.
  Abstract. This paper presents the first steps towards the design of an application called FoxyTag, allowing a driver to post a virtual tag on a speed camera in order to notify other drivers. A trust mechanism allows the automatic computation of the trustworthiness of a given tag. This results in a trustworthy architecture, freely accessible by anyone that owns a mobile phone and a GPS.
  
  

• GeoVTag: a User’s Guide Michel Deriaz. ASG technical report 06. 2006.
  Abstract. This paper presents GeoVTag, an application running on a mobile phone that allows the user to publish anywhere on Earth virtual tags. Every user in the neighborhood of such a publication point will get the message. It is a kind of blog, in which editors and readers share the same physical place. GeoVTag allows tag edition and reading, but has also some additional functionalities like a digital compass, a radar to find and display graphically all neighboring tags, a tracker to record GPS data, a marker function that sends automatically time-totime a tag, and a "goto" function that directs a user to a specific tag by showing graphically the direction to follow and the remaining distance.
  
  

• Trust and Security for Spatial Messaging Michel Deriaz. ASG technical report 06. 2006.
  Abstract. Spatial messaging is a term that defines the virtual publication of data in physical places. Anyone in the neighborhood of such a publication point gets the message. Architectures allowing users to publish freely spatial messages already exist. However, experiences realized with volunteers showed that there is only little interest in posting such notes. To our view, the main reason is that there is currently no trust mechanism which informs about the reliability of the messages, thus preventing any serious application. Filling this gap will promote the success of spatial messaging, and the growing success of localization and mobile techniques will provide a good support for this concept. After a general presentation conducted by hypothetical scenarios to show the potential impact of spatial messaging, we will discuss how to build a trust model, and propose a first move to a concrete architecture.
  
  

• What is Trust? My Own Point of View Michel Deriaz. ASG technical report 06. 2006.
  Abstract. What is trust? From an intuitive global definition on how humans perceive trust, to a real and practical implementation, the way is long. Most people stop their quest of an answer at midway, in the field of formal, mathematical and theoretical models. And the path is not unique, each researcher taking a different way. This paper presents the author’s own way. Trying to stay as close as possible to the human notion of trust, we discuss also how to take into account the time component, since people give intuitively more importance to recent or scattered events.
  
  

• Towards Trusted Semantic Service Computing Michel Deriaz. 2005.
  Abstract. This paper describes a new prototype of a semantic Service Oriented Architecture (SOA) called Spec Services. Instead of publishing their API through a protocol like SOAP, as Web Services do, services can register to a service manager a powerful syntactic description or even semantic description of their functional capabilities. The client entity will then send a syntactic or semantic description of its requirements to the service manager, which will try to find an appropriate formerly registered service and to bind them together. Today our service manager can deal with two languages: regular expressions, which is probably the most powerful syntactic-only description language; and Prolog, which is purely semantic. This implementation is made, since its beginning, with evolution in mind, i.e. to easily support integration of new additional formal languages and to provide support for non-functional properties of services. This paper proposes also a trust-based extension of our architecture in order to deploy effectively these self-describing services in an uncertain environment.
  
  

• Semantic Service Oriented Architecture Michel Deriaz, Giovanna Di Marzo Serugendo. 2004.
  Abstract. This paper describes a new prototype of a semantic Service Oriented Architecture (SOA) called Spec Services. Instead of publishing their API through a protocol like SOAP, as Web Services do, services can register to a service manager a powerful syntactic description or even semantic description of their capabilities. The client entity will then send a syntactic or semantic description of its requirements to the service manager, which will try to find an appropriate formerly registered service and bind them together. Today our service manager can deal with two languages: regular expressions, which is probably the most powerful syntactic-only description language; Prolog, which is only semantic. Nevertheless, this implementation is made, since its beginning, with evolution in mind, i.e. to easily support integration of new additional formal languages.
  
  

Position papers

• A thesis proposition: Service Oriented Computing in a P2P architecture Michel Deriaz. 2005.
  Abstract. This position paper is an attempt to describe my future thesis work. It shortly describes the work that has already been done, and then suggests different research directions. Currently we have an architecture in which services register with a service manager and entities queries the service manager in order to find a service that is able to fulfill a specific need. Unlike traditional Web services that use APIs to communicate, our architecture uses specification files allowing powerful syntactic and even semantic descriptions of services or requests. However, in client-server architectures, the clients act independently from the others and this prevents collaboration between them. This thesis proposition suggests a decentralized system, highly dynamic, accessible by humans and machines, and proposes to study issues like semantic interoperability, trust, and rewarding of good peers.
  
  

Delivrables, drafts, and other for the EDOS project

• Using Features To Structure the F/OSS Distribution Process Michel Pawlak, Ciarán Bryce, Michel Deriaz. Draft. 2005.
  
  

• Towards an Edos API: Modelling the F/OSS Process Michel Pawlak, Ciarán Bryce, Michel Deriaz. Draft. 2005.
  Abstract. The goal of Edos is to improve F/oss production and code distribution processes. A prerequisite to this is to formally distinguish the different concepts in the processes, the roles undertaken by users, the data types used, and their inter-relationships. This allows one to determine the data that must always be distributed together from those that need not be; from a security and management viewpoint, it formalises the privileges and information that a particular user requires at any given time. This note proposes elements of a model for F/oss that makes roles and data types explicit. We hope that it can serve as a basis for future discussion.
  
  

• Code Distribution Process - Definition of Evaluation Metrics Ciarán Bryce, Michel Pawlak, Michel Deriaz - Universite de Geneve; Serge Abiteboul, Boris Vrdoljak - INRIA Gemo Project; Tova Milo, Assaf Sagi - Tel-Aviv University; Stephane Lauriere, Florent Villard, Radu POP - MandrakeSoft. 2005.
  
  

• Edos Glossary Ciarán Bryce, Michel Deriaz, Michel Pawlak. 2005.