Orange S.A.

About: Orange S.A. is a company organization based out in Paris, France. It is known for research contribution in the topics: Terminal (electronics) & Signal. The organization has 6735 authors who have published 9190 publications receiving 156440 citations. The organization is also known as: Orange SA & France Télécom.

Design by Contract to Improve Software Vigilance

Abstract: Design by contract is a lightweight technique for embedding elements of formal specification (such as invariants, pre and postconditions) into an object-oriented design. When contracts are made executable, they can play the role of embedded, online oracles. Executable contracts allow components to be responsive to erroneous states and, thus, may help in detecting and locating faults. In this paper, we define vigilance as the degree to which a program is able to detect an erroneous state at runtime. Diagnosability represents the effort needed to locate a fault once it has been detected. In order to estimate the benefit of using design by contract, we formalize both notions of vigilance and diagnosability as software quality measures. The main steps of measure elaboration are given, from informal definitions of the factors to be measured to the mathematical model of the measures. As is the standard in this domain, the parameters are then fixed through actual measures, based on a mutation analysis in our case. Several measures are presented that reveal and estimate the contribution of contracts to the overall quality of a system in terms of vigilance and diagnosability

Smart card based system for telephone-securized transactions

Abstract: A Smart Card Based System for telephone-securized transactions. The system includes a telephone terminal (10) connected to a server (30) and a package or unit (40) incorporating a keypad (42), a smart card (48) and sound signal transmission device. The transmission of the information of the card to the server takes place by way of sound signals and the telephone terminal. In the other direction, the information is addressed in vocal manner to the user, who types them on the keypad (42) of the unit (40). Application to securized teletransactions, particularly electronic funds transfer.

COOL: system support for distributed programming

Abstract: istributed systems are by their very nature large and complex applications requiring the interaction of many individual c o m p o n e n t s scattered throughout a distributed collection of hosts which are often physically dispersed. Interaction is usually modeled on a message-passing abstraction in which services are requested by sending a request message to a service provider and receiving an asynchronous or synchronous reply. Service providers are often large-grained encapsulated entities, whose interface is defined by its message protocol. Internal synchronization of multiple competing requests is handled by the service provider either by message queuing or by language synchronization primitives. Such systems are natural candidates for the objectoriented model of software development simply because the way most of them are built maps closely to the objectoriented model. Service providers are large-grained, active objects; message protocols define an adhoc type interface, and message passing is a low-level mechanism that supports method invocation. This obvious mapping has led many groups to attempt to extend existing object-oriented languages with support for distributed objects, either by adding remote messagepassing facilities (based on RPC) or by supporting distributed objects [2, 11]. This approach has had mixed success. On the one hand it has demonstrated that the object-oriented languages provide sufficient support for building distributed applications. However, because the efficiency of such an approach has been so poor, it has served as a proof of concept but has failed to provide the break through for which many in the distributed-systems community have hoped. This inefficiency is mainly caused by a mismatch between the services and abstractions that systems provide, and those that languages offer. System services are often generic, designed to support multiple uses, and achieving this with a lowestcommon-denominator solution. Also, the majority of existing operating systems provide abstractions that were never designed to support modern programming languages and, in particular, were never designed to support distributed applications. For example , ob j ec t -o r i en t ed languages deal with f ine-grained objects. The majority of modern systems provide an abstraction of an address space as the smallest systemsupported concept. It is the compiler's job to match the fine-grained language model to the coarse-grained system model. For a single address space application this is fine; however, for distributed applications, spanning multiple address spaces, the compiler support breaks down because the compiler is not aware of the environment outside a single address space. Equally, some languages support lightweight activities or active objects; again, most systems support a heavier notion, a process. Mapping between the two is a complex and often costly task. Finally, current operating systems provide distributed interprocess communication using protocols designed for unre l iable networks and often implemented as an \"add-on\" feature. These communication mechanisms are often too costly to support applications built of fine-grained objects, working in a tightly coupled manner and using interobject invocation.

Public key cryptography and RFID tags

Abstract: When exploring solutions to some of the formidable security problems facing RFID deployment, researchers are often willing to countenance the use of a strong symmetric primitive such as the AES. At the same time it is often claimed that public key cryptography cannot be deployed on low-cost tags. In this paper we give a detailed analysis of the GPS identification scheme. We show that with regards to all three attributes of space, power, and computation time, the on-tag demands of GPS identification compare favourably to the landmark AES implementation by Feldhofer et al.. Thus, assumed limits to implementing asymmetric cryptography on low-end devices may need to be re-evaluated.