The Experts below are selected from a list of 12264 Experts worldwide ranked by ideXlab platform

Luc Moreau - One of the best experts on this subject based on the ideXlab platform.

  • a fault tolerant Directory Service for mobile agents based on forwarding pointers
    ACM Symposium on Applied Computing, 2002
    Co-Authors: Luc Moreau
    Abstract:

    A reliable communication layer is an essential component of a mobile agent system. We present a new fault-tolerant Directory Service for mobile agents, which can be used to route messages to them. The Directory Service, based on a technique of forwarding pointers, introduces some redundancy in order to ensure resilience to stopping failures of nodes containing forwarding pointers; in addition, it avoids cyclic routing of messages, and it supports a technique to collapse chains of pointers that allows direct communications between agents. We have formalised the algorithm and derived a fully mechanical proof of its correctness using the proof assistant Coq; we report on our experience of designing the algorithm and deriving its proof of correctness. The complete source code of the proof is made available from the WWW.

  • distributed Directory Service and message routing for mobile agents
    Science of Computer Programming, 2001
    Co-Authors: Luc Moreau
    Abstract:

    Research about networks and agents has identified the need for a layer that provides a uniform protocol to communicate with fixed and mobile agents. In order to preserve the compatibility with existing infrastructures, proposed solutions have involved a "home agent", which forwards messages to a mobile entity. The mechanism of a home agent puts a burden on the infrastructure, which may hamper the scalability of the approach, in particular, in massively distributed systems, such as the amorphous computer or the ubiquitous/pervasive computing environment. Free from any compatibility constraint, we have designed an algorithm to route messages to mobile agents that does not require any fixed location. The algorithm has two different facets: a distributed Directory Service that maintains distributed information about the location of a mobile agent, and a message router that uses the Directory Service to deliver messages to a mobile agent. Two properties of the algorithm were established. The safety property ensures that messages are delivered to the agent they were aimed at, whereas the liveness property guarantees that messages eventually get delivered. A mechanical proof of the properties was carried out using the proof assistant Coq.

  • a fault tolerant Directory Service for mobile agents based on forwarding pointers
    Scalable Computing: Practice and Experience, 2001
    Co-Authors: Luc Moreau
    Abstract:

    A reliable communication layer is an essential component of a mobile agent system. We present a new fault-tolerant Directory Service for mobile agents, which can be used to route messages reliably to them, even in the presence of failures of intermediary nodes between senders and receivers. The Directory Service, based on a technique of forwarding pointers, introduces some redundancy in order to ensure resilience to stopping failures of nodes containing forwarding pointers; in addition, it avoids cyclic routing of messages, and it supports a technique to collapse chains of pointers that allows direct communication between agents. We have formalised the algorithm and derived a fully mechanical proof of its correctness using the proof assistant Coq; we report on our experience of designing the algorithm and deriving its proof of correctness. The complete source code of the proof is made available from the WWW.

Kieran Mccorry - One of the best experts on this subject based on the ideXlab platform.

  • Microsoft Exchange Server 2003, Deployment and Migration SP1 and SP2 - 2 – Active Directory Connector Synchronization
    Microsoft® Exchange Server 2003 Deployment and Migration, 2004
    Co-Authors: Kieran Mccorry
    Abstract:

    This chapter explores the basic operation of the Active Directory Connector, and how it synchronizes data from Exchange 5.5 to Active Directory and vice versa. A clear and complete understanding of Active Directory Connector operation is the key to any Exchange 5.5-to-Exchange 2003 migration project. The Active Directory Connector is one of the most powerful tools available to the messaging consultant. Exchange 2003 doesn't have its own built-in Directory Service; instead it uses the Active Directory. During a migration exercise from a legacy Exchange 5.5 environment to Exchange 2003, one of the most important aspects of coexistence is that of synchronizing Directory information between the Exchange 5.5 Directory Service and the Windows 2003 Active Directory. The Active Directory Connector does this, as it maps the Exchange 5.5 Directory Service object types to the Active Directory, and vice versa. The Active Directory Connector available with Exchange 2003 is not that much different from the Active Directory Connector that was available with Exchange 2000. The core functionality remains more or less the same, and only minor aspects of its operation have changed, and it includes a number of bug fixes.

  • Microsoft Exchange Server 2003, Deployment and Migration SP1 and SP2 - 4 – The Site Replication Service
    Microsoft® Exchange Server 2003 Deployment and Migration, 2004
    Co-Authors: Kieran Mccorry
    Abstract:

    The Site Replication Service (SRS) is a poorly understood component of Exchange 2003 and Exchange 2000. It is perceived to be a component that allows an Exchange 2003 server to synchronize Directory information with an Exchange 5.5 server. However, the SRS's role is merely to allow an Exchange 2003 server to participate in Exchange 5.5-style Directory replication. Only the Active Directory Connector provides the mechanism to perform Directory synchronization between the Exchange 5.5 Directory Service and the Active Directory. The SRS has nothing to do with this exchange of information. The SRS presents itself as an Exchange 5.5 Directory Service to other Exchange 5.5 servers but runs on an Exchange 2003 server. Using the SRS to provide a shadow Exchange 5.5 Directory Service allows other Exchange 5.5 servers to continue with Exchange 5.5 Directory replication to a particular server in the same way that they always have, even if that particular server has been upgraded to Exchange 2003. The SRS works with the Active Directory Connector to make the whole concept of Exchange 5.5 Directory Service-to-Active Directory synchronization easier.

  • 2 active Directory connector synchronization
    Microsoft® Exchange Server 2003 Deployment and Migration, 2004
    Co-Authors: Kieran Mccorry
    Abstract:

    This chapter explores the basic operation of the Active Directory Connector, and how it synchronizes data from Exchange 5.5 to Active Directory and vice versa. A clear and complete understanding of Active Directory Connector operation is the key to any Exchange 5.5-to-Exchange 2003 migration project. The Active Directory Connector is one of the most powerful tools available to the messaging consultant. Exchange 2003 doesn't have its own built-in Directory Service; instead it uses the Active Directory. During a migration exercise from a legacy Exchange 5.5 environment to Exchange 2003, one of the most important aspects of coexistence is that of synchronizing Directory information between the Exchange 5.5 Directory Service and the Windows 2003 Active Directory. The Active Directory Connector does this, as it maps the Exchange 5.5 Directory Service object types to the Active Directory, and vice versa. The Active Directory Connector available with Exchange 2003 is not that much different from the Active Directory Connector that was available with Exchange 2000. The core functionality remains more or less the same, and only minor aspects of its operation have changed, and it includes a number of bug fixes.

  • Microsoft Exchange Server 2003, Deployment and Migration SP1 and SP2 - 2 – Active Directory Connector Synchronization
    Microsoft® Exchange Server 2003 Deployment and Migration, 2004
    Co-Authors: Kieran Mccorry
    Abstract:

    This chapter explores the basic operation of the Active Directory Connector, and how it synchronizes data from Exchange 5.5 to Active Directory and vice versa. A clear and complete understanding of Active Directory Connector operation is the key to any Exchange 5.5-to-Exchange 2003 migration project. The Active Directory Connector is one of the most powerful tools available to the messaging consultant. Exchange 2003 doesn't have its own built-in Directory Service; instead it uses the Active Directory. During a migration exercise from a legacy Exchange 5.5 environment to Exchange 2003, one of the most important aspects of coexistence is that of synchronizing Directory information between the Exchange 5.5 Directory Service and the Windows 2003 Active Directory. The Active Directory Connector does this, as it maps the Exchange 5.5 Directory Service object types to the Active Directory, and vice versa. The Active Directory Connector available with Exchange 2003 is not that much different from the Active Directory Connector that was available with Exchange 2000. The core functionality remains more or less the same, and only minor aspects of its operation have changed, and it includes a number of bug fixes.

G Yuval - One of the best experts on this subject based on the ideXlab platform.

  • a secure Directory Service based on exclusive encryption
    Annual Computer Security Applications Conference, 2002
    Co-Authors: John R. Douceur, Atul Adya, Josh Benaloh, William J Bolosky, G Yuval
    Abstract:

    We describe the design of a Windows file-system Directory Service that ensures the persistence, integrity, privacy, syntactic legality, and case-insensitive uniqueness of the names it indexes. Byzantine state replication provides persistence and integrity, and encryption imparts privacy. To enforce Windows' baroque name syntax - including restrictions on allowable characters, on the terminal character, and on several specific names - we develop a cryptographic process, called "exclusive encryption," that inherently excludes syntactically illegal names and that enables the exclusion of case-insensitively duplicate names without access to their plaintext. This process excludes entire names by mapping the set of allowed strings to the set of all strings, excludes certain characters through an amended prefix encoding, excludes terminal characters through varying the prefix coding by character index, and supports case-insensitive comparison of names by extracting and encrypting case information separately. We also address the issues of hiding name-length information and access-authorization information, and we report a newly discovered problem with enforcing case-insensitive uniqueness for Unicode names.

Radia Perlman - One of the best experts on this subject based on the ideXlab platform.

Sun Tanfeng - One of the best experts on this subject based on the ideXlab platform.

  • Desing and Improvement of PMI Directory
    Information Security and Communications Privacy, 2008
    Co-Authors: Sun Tanfeng
    Abstract:

    Privilege Management Infrastructure(PMI) is an important part of the information security infrastructure.And the performance of a Directory Service,which is one of the key factors of the PMI system,directly affects the performance of the entire system.By studying and analyzing the efficiency of the search operation in LDAP entire in consideration of the entire PMI system,this paper makes some recommendations for building an efficient Directory.