French Institute for Research in Computer Science and Automation

About: French Institute for Research in Computer Science and Automation is a government organization based out in Le Chesnay, France. It is known for research contribution in the topics: Context (language use) & Population. The organization has 13012 authors who have published 38653 publications receiving 1318995 citations. The organization is also known as: INRIA & Institute for national research in information science and automatic control.

An authorization scheme for distributed object systems

Abstract: Addresses the problem of distributed object system protection. A new authorization scheme is presented and described, based on the collaboration between a central authorization server and security kernels located on each site of the system. A novel approach to access rights management for such an architecture is detailed, based on a new kind of access rights and a new scheme of privilege delegation. This authorization scheme can be adapted to various security policies, including multilevel policies such as that of Bell & LaPadula (1975). An extension of the Bell-LaPadula model to distributed object systems is presented and its implementation using the authorization scheme is described.

Extension of Metric-Based Anisotropic Mesh Adaptation to Time-Dependent Problems Involving Moving Geometries

Abstract: This paper deals with anisotropic mesh adaptation applied to unsteady simulations, especially those involving moving geometries. Anisotropic metric-based mesh adaptation is an efficient strategy to reduce the extensive CPU time currently required by such simulations in the perspective of performing this kind of computations on a daily basis in an industrial context. In this work, we detail the extension of the multiscale anisotropic mesh adaptation, i.e., a control of the interpolation error in L norm, to unsteady flows thanks to an enhanced version of the fixed-point algorithm. The parallelization of the whole mesh adaptation plate-form is also discussed. The efficiency of the approach is emphasized on three-dimensional blast problems. The last part of this paper is concerned with the extension of this new algorithm to moving mesh problems. We explain how the mesh displacement is taken into account in the adaptation strategy. The method is illustrated on three-dimensional analytical examples and on a two dimensional blast computation.

Safely composing security protocols

Abstract: Security protocols are small programs that are executed in hostile environments. Many results and tools have been developed to formally analyze the security of a protocol. However even when a protocol has been proved secure, there is absolutely no guarantee if the protocol is executed in an environment where other protocols, possibly sharing some common identities and keys like public keys or long-term symmetric keys, are executed. In this paper, we show that whenever a protocol is secure, it remains secure even in an environment where arbitrary protocols are executed, provided each encryption contains some tag identifying each protocol, like e.g. the name of the protocol.