User Access Control Research Articles

A purpose‐based access control in native XML databases

SUMMARYWith the growing importance of privacy in data access, much research has been done on the privacy protecting technology in the recent years. Developing an access control model and related mechanisms to support a selective access data has become important. The extensible markup language (XML) is rapidly emerging as the new standard language for semi‐structured data representation and exchange on the Internet with more and more information being distributed in XML format. In this paper, we present a comprehensive approach for privacy preserving access control based on the notion of purpose. In our model, purpose information associated with a given data element in an XML document specifies the intended use of the data elements. An important issue addressed in this paper is the granularity of data labeling for data elements in XML documents and tree databases with which purposes can be associated. We address this issue in native XML databases and propose different labeling schemes for XML documents. We also propose an approach to represent purpose information to support access control based on purpose information. Our proposed solution relies on usage access control models as well as the components that are based on the notions of the purpose information used in subjects and objects. Finally, comparisons with related works are analysed. Copyright © 2011 John Wiley & Sons, Ltd.

An Efficient Mutual Authentication and Access Control Scheme for Wireless Sensor Networks in Healthcare

Wireless sensor networks (WSNs) will play an active role in the 21th Century Healthcare IT to reduce the healthcare cost and improve the quality of care. The protection of data confidentiality and patient privacy are the most critical requirements for the ubiquitous use of WSNs in healthcare environments. This requires a secure and lightweight user authentication and access control. Symmetric key - based access control is not suitable for WSNs in healthcare due to dynamic network topology, mobility, and stringent resource constraints. In this paper, we propose a secure, lightweight public key - based security scheme, Mutual Authentication and Access Control based on Elliptic curve cryptography (MAACE). MAACE is a mutual authentication protocol where a healthcare professional can authenticate to an accessed node (a PDA or medical sensor) and vice versa. This is to ensure that medical data is not exposed to an unauthorized person. On the other hand, it ensures that medical data sent to healthcare professionals did not originate from a malicious node. MAACE is more scalable and requires less memory compared to symmetric key-based schemes. Furthermore, it is much more lightweight than other public key-based schemes. Security analysis and performance evaluation results are presented and compared to existing schemes to show advantages of the proposed scheme.

Achieving distributed user access control in sensor networks

User access control in sensor networks defines a process of granting user an access right to the stored information. It is essential for future real sensor network deployment in which sensors may provide users with different services in terms of data and resource accesses. A centralized access control mechanism requires the base station to be involved whenever a user requests to get authenticated and access the information stored in the sensor node, which is inefficient, not scalable, and is exposed to many potential attacks along long communication paths. In this paper, we propose a distributed user access control under a realistic adversary model in which sensors can be compromised and user may collude. We split the access control into local authentication conducted by a group of sensors physically close to a user, and a light remote authentication based on the endorsement of the local sensors. We implement the access control protocols on a testbed of TelosB motes. Our analysis and experimental results show that our schemes are feasible for real access control requirements.

Design and implementation of grid computation platform for water applications

Considering the dilemma for the existing water application system in complex business applications,the authors,in combination with the water problem feature,designed and developed the grid of water application.The system provided a B/S and C/S combination service model,realized user access control based on role,monitored the node in real-time by heartbeat mechanism,and achieved task management based on workflow.

Back to Basics: Understanding Operating Systems and Network Operating Systems

Back to Basics: Understanding Operating Systems and Network Operating Systems

Secure distribution for high resolution remote sensing images

The use of remote sensing images collected by space platforms is becoming more and more widespread. The increasing value of space data and its use in critical scenarios call for adoption of proper security measures to protect these data against unauthorized access and fraudulent use. In this paper, based on the characteristics of remote sensing image data and application requirements on secure distribution, a secure distribution method is proposed, including users and regions classification, hierarchical control and keys generation, and multi-level encryption based on regions. The combination of the three parts can make that the same remote sensing images after multi-level encryption processing are distributed to different permission users through multicast, but different permission users can obtain different degree information after decryption through their own decryption keys. It well meets user access control and security needs in the process of high resolution remote sensing image distribution. The experimental results prove the effectiveness of the proposed method which is suitable for practical use in the secure transmission of remote sensing images including confidential information over internet.

U-Healthcare 시스템을 위한 RBAC-WS

Information technology is being applied to the development of ubiquitous healthcare system, which provides both efficient patient care and convenient treatment regardless of patient`s location. However, the increasing number of users and medical information give rise to the problem of user management and the infringement of privacy. In order to address this problem we propose a user access scheme based on the RBAC (Role Based Access Control) model. The preceding trust management model for Grid security, FAS(Federation Agent Server), was analyzed and extended to provide supplementary functions for role-based access control in u-Healthcare system. The RBAC model provides efficient user management and access control, but very vulnerable in case when one with valid role tries to leak confidential inner medical information. In order to resolve this problem, a RBAC-WS (Work Status with RBAC) model has been additionally developed which allows only qualified staffs to access the system while on duty. Th proposed RBAC and RBAC-WS model have been merged together and applied to the PACS (Picture Archiving and Communication System).

PEACE: A Novel Privacy-Enhanced Yet Accountable Security Framework for Metropolitan Wireless Mesh Networks

Recently, multihop wireless mesh networks (WMNs) have attracted increasing attention and deployment as a low-cost approach to provide broadband Internet access at metropolitan scale. Security and privacy issues are of most concern in pushing the success of WMNs for their wide deployment and for supporting service-oriented applications. Despite the necessity, limited security research has been conducted toward privacy preservation in WMNs. This motivates us to develop PEACE, a novel Privacy-Enhanced yet Accountable seCurity framEwork, tailored for WMNs. On one hand, PEACE enforces strict user access control to cope with both free riders and malicious users. On the other hand, PEACE offers sophisticated user privacy protection against both adversaries and various other network entities. PEACE is presented as a suite of authentication and key agreement protocols built upon our proposed short group signature variation. Our analysis shows that PEACE is resilient to a number of security and privacy related attacks. Additional techniques were also discussed to further enhance scheme efficiency.

Security architecture and methodology for authorisation of mobile agents

One approach to authorisation of mobile agents is to use extensible access control mark-up language (XACML) policies by assigning roles to agents and then enforcing role-based authorisation. In this paper we show how traditional XACML polices, used for user access control in distributed environments, can be used for mobile agents' access control. We use such polices to manage delegation of access rights from users to agents, while at the same time following the core principles of the XACML standard. We also propose a combination of policies that map users to their mobile agents and make access control decisions for mobile agents by evaluating complex policy sets. We have identified all architectural components along with the operations required for enforcement of authorisations of mobile agents during execution.

A web-based system for near real-time surveillance and space-time cluster analysis of foot-and-mouth disease and other animal diseases

Considerable attention has been given lately to the need for global systems for animal disease surveillance that support real-time assessment of changing temporal-spatial risks. Until recently, however, prospects for development of such systems have been limited by the lack of informatics tools and an overarching collaboration framework to enable real-time data capturing, sharing, analysis, and related decision-making. In this paper, we present some of the tools of the FMD BioPortal System (www.fmd.ucdavis.edu/bioportal), which is a web-based system that facilitates near real-time information sharing, visualization, and advanced space-time cluster analysis for foot-and-mouth disease (FMD). Using this system, FMD information that is collected and maintained at various data acquisition and management sites around the world can be submitted to a data repository using various mutually agreed upon Extensible Markup Language (XML) formats, including Health Level Seven (HL7). FMD BioPortal makes available a set of advanced space-time cluster analysis techniques, including scan statistic-based methods and machine learning-based clustering methods. These techniques are aimed at identifying local clusters of disease cases in relation to the background risk. Data and analysis results can be displayed using a novel visualization environment, which supports multiple views including GIS, timeline, and periodical patterns. All FMD BioPortal functionalities are accessible through the Web and data confidentiality can be secured through user access control and computer network security techniques such as Secure Sockets Layer (SSL). FMD BioPortal is currently operational with limited data routinely collected by the Office International des Epizooties, the GenBank, the FMD World Reference Laboratory in Pirbright, and by the FMD Laboratory at the University of California in Davis. Here we describe technical attributes and capabilities of FMD BioPortal and illustrate its functionality by analyzing and displaying information from a simulated FMD epidemic in California.

Better Control of User Web Access of Electronic Resources

A Web portal is a convenient way to allow access to electronic resources. However, for a large, geographically dispersed, and mobile user population, it can be difficult to track users' access of the system. Legal liability and the need for valid usage statistics make it important to limit access to legitimate users. The combination of proper access logging and the use of open source software allow the matching of user names to geographic locations. By analyzing geography-based usage patterns, suspicious activity can be identified and corrective actions taken. This paper describes how these techniques were used at the Uniformed Services University of the Health Sciences (USUHS) to better control and monitor user access.

A platform for proving family oriented RESTful services hosted at home

Online Internet sites offer services and rich data mash-ups that attract many users to upload their content, social connections and personal information to the cloud. With privacy considerations in mind and the need for services that are targeted for family usage, we present an architecture that allows users to host not only their content but also the actual services at their home infrastructure. The system, which is based on open and standardized Web technologies, allows the home services to be selectively opened to remote users and semi-trusted external services, for exporting part of their functionality. Fine-grained access rights are built into the system, which also leverages external social networking sites for making access control and invitation interface easier for the end users. A prototype implementation of the full system, where family services are actually running on a smart phone located at home, is presented. The work proves the feasibility and easiness of using RESTful services in the home environment, due to the clarity of their interfaces.

Design and implementation of MobiSEC: A complete security architecture for wireless mesh networks

Wireless mesh networks (WMNs) have emerged recently as a technology for next-generation wireless networking. They consist of mesh routers and clients, where mesh routers are almost static and form the backbone of WMNs. WMNs provide network access for both mesh and conventional clients. In this paper we propose MobiSEC, a complete security architecture that provides both access control for mesh users and routers as well as a key distribution scheme that supports layer-2 encryption to ensure security and data confidentiality of all communications that occur in the WMN. MobiSEC extends the IEEE 802.11i standard exploiting the routing capabilities of mesh routers; after connecting to the access network as generic wireless clients, new mesh routers authenticate to a central server and obtain a temporary key that is used both to prove their credentials to neighbor nodes and to encrypt all the traffic transmitted on the wireless backbone links. A key feature in the design of MobiSEC is its independence from the underlying wireless technology used by network nodes to form the backbone. Furthermore, MobiSEC allows seamless mobility of both mesh clients and routers. MobiSEC has been implemented and integrated in MobiMESH, a WMN implementation that provides a complete framework for testing and analyzing the behavior of a mesh network in real-life environments. Moreover, extensive simulations have been performed in large-scale network scenarios using Network Simulator. Numerical results show that our proposed architecture considerably increases the WMN security, with a negligible impact on the network performance, thus representing an effective solution for wireless mesh networking.

Role-Based Access Control in a Data Grid Using the Storage Resource Broker and Shibboleth

In this paper, we propose a role-based access control (RBAC) system for data resources in the Storage Resource Broker (SRB). The SRB is a Data Grid management system, which can integrate heterogeneous data resources of virtual organizations (VOs). The SRB stores the access control information of individual users in the Metadata Catalog (MCAT) database. However, because of the specific MCAT schema structure, this information can only be used by the SRB applications. If VOs also have many non-SRB applications, each with its own storage format for user access control information, it creates a scalability problem with regard to administration. To solve this problem, we developed a RBAC system with Shibboleth, which is an attribute authorization service currently being used in many Grid environments. Thus, the administration overhead is reduced because the role privileges of individual users are now managed by Shibboleth, not by MCAT or applications. In addition, access control policies need to be specified and managed across multiple VOs. For the specification of access control policies, we used the Core and Hierarchical RBAC profile of the eXtensible Access Control Markup Language (XACML); and for distributed administration of those policies, we used the Object, Metadata and Artifacts Registry (OMAR). OMAR is based on the e-business eXtensible Markup Language (ebXML) registry specifications developed to achieve interoperable registries and repositories. Our RBAC system provides scalable and fine-grain access control and allows privacy protection. Performance analysis shows that our system adds only a small overhead to the existing security infrastructure of the SRB.

Privacy preserving document indexing infrastructure for a distributed environment

To carry out work assignments, small groups distributed within a larger enterprise or collaborative community often need to share documents among themselves while shielding those documents from others' eyes. In this situation, users need an indexing facility that can quickly locate relevant documents that they are allowed to access, without (1) leaking information about the remaining documents, (2) imposing a large management burden as users, groups, and documents evolve, or (3) requiring users to agree on a central completely trusted authority. In order to achieve this aim user access levels and access control have to be reflected in the index structures and/or retrieval algorithms as well as in ranking the search results. My Ph.D. work focuses on building up an indexing infrastructure which supports confidential indexing, sharing and retrieval of unstructured information which is spread over a number of distributed access-controlled collections. In order to allow for effective and efficient indexing and retrieval in these settings, it considers aspects of confidentiality preservation within an outsourced inverted index, a DHT index structure in P2P networks as well as confidential top-k information retrieval.

Home gateway operating model using reference monitor for enhanced user comfort and privacy

In home network environments, user comfort and privacy are key prerequisites for customer satisfaction and data security. Although methods such as ACLs and others control the user-access for home network devices, most existing methods have yet to satisfactorily address the issues related to a user's comfort level and his or her protection of privacy. Therefore, this paper outlines the proposal for home gateway operating model using reference monitor in an OSGi service platform, whose goal is to enhance the operation required to efficiently meet a user's access, convenience, and privacy concerns. The reference monitor is a collection of access controls for objects, and is also capable of providing the facilities for access control. Furthermore, it adds the element of comfort to user access control, because it is intended as a core part of how subjects interact with objects. The proposed model is based on an RBAC model to effectively manage access control. Its policy is classified into two types (e.g., user-role assignment policy and permission-role assignment policy) in an attempt to not only better protect user privacy, but also to improve the performance of the policy operation. It is argued that the new home gateway model provides sufficient and effective guidelines to suggest future access control policies.

Integrating Usage Control with SIP‐Based Communications

The Session Initiation Protocol (SIP) is a signaling protocol used for establishing and maintaining communication sessions involving two or more participants. SIP was initially designed for voice over IP and multimedia conferencing, and then was extended to support other services such as instant messaging and presence management. Today, SIP is also adopted to be used with 3G wireless networks, thus it becomes an integral protocol for ubiquitous environment. SIP has various methods that support a variety of applications such as subscribing to a service, notification of an event, status update, and location and presence services. However, when it comes to security, the use of wireless and mobile communication technologies and the pervasive nature of this environment introduce higher risks to security than that of the old simple environment. In this paper, we introduce new architecture that implements a new type of access control called usage access control (UCON) to control the access to the SIP‐based communication at preconnection, during connection, and postconnection. This will enable prescribers of SIP services to control who can identify their locations to approve or disapprove their subsequent connections, and to also set some parameters to determine whether a certain communication can continue or should terminate.

DRM: Digital rights management or digital restrictions management?

AbstractDigital rights management (DRM) constitutes the technological measures by which information providers control user access to electronic products to prevent the downloading or printing of online content in amounts that could substitute for product subscriptions or purchases. DRM limitations on the types of uses and their frequency are encoded directly in the products or the hardware needed to use them. This challenges the fair use provisions of copyright law, which offer room for interpretation on whether particular uses compromise the commercial value of copyrighted content. Since DRM measures are part of licensing agreements between vendors and users, they override fair use. This session will provide the rationale for DRM, explain the conflicts between copyright holder and user rights arising from DRM implementation, discuss legislative issues, and suggest alternatives to DRM that might satisfy both parties.

APPROXIMATE QUERY PROCESSING USING MULTILAYERED DATA MODEL TO HANDLE ENVIRONMENTAL CONSTRAINTS, PRIVACY AND AVOIDING INFERENCES

In this paper, we describe a query approximation system which uses the Multi-Layered Database (MLDB), a collection of summarized relational data generated using domain-based concept hierarchies. The system generates approximate answers to queries to handle environmental constraints and access control levels, thus preserving the privacy and security of data. Using concept hierarchy (CH), we generalize attributes to transform base relations to different layers of summarized relations corresponding to access control levels. The summary databases thus formed are the compression of the tuples in the main database using the CH constructed using the domain set. The query is rewritten by traversing the MLDB layers according to the user's access control level. We present summarization methods, query rewriting algorithms, implementation and experimental results of the system. In addition, we analyze some of the known inferences in Multi Level Secure (MLS) databases and then proceed to explore their effects on an approximate query processor that uses the MLDB model. The common relationships among inferential queries are found by analyzing them, and are used in possible solutions to detect and prevent inference problems. These patches are added to the query processor in MLDB to form a system that provides approximate results by preserving privacy and at the same time block the possible inferences. We have observed that these extra patches introduce only very small overheads in the MLDB generation and query processing.

Trust Negotiation in Identity Management

Most organizations require the verification of personal information before providing services, and the privacy of such information is of growing concern. The authors show how federated identity management systems can better protect users' information when integrated with trust negotiation. In today's increasingly competitive business environment, more and more leading organizations are building Web-based infrastructures to gain the strategic advantages of collaborative networking. However, to facilitate collaboration and fully exploit such infrastructures, organizations must identify each user in the collaborative network as well as the resources each user is authorized to access. User identification and access control must be carried out so as to maximize user convenience and privacy without increasing organizations1 operational costs. A federation can serve as the basic context for determining suitable solutions to this issue. A federation is a set of organizations that establish trust relationships with respect to the identity information-the federated identity information-that is considered valid. A federated identity management system (idM) provides a group of organizations that collaborate with mechanisms for managing and gaining access to user identity information and other resources across organizational boundaries