12,853 research outputs found
Integrity Constraints in Trust Management
We introduce the use, monitoring, and enforcement of integrity constraints in
trust management-style authorization systems. We consider what portions of the
policy state must be monitored to detect violations of integrity constraints.
Then we address the fact that not all participants in a trust management system
can be trusted to assist in such monitoring, and show how many integrity
constraints can be monitored in a conservative manner so that trusted
participants detect and report if the system enters a policy state from which
evolution in unmonitored portions of the policy could lead to a constraint
violation.Comment: An extended abstract appears in the proc. of the 10th ACM Symp. on
Access Control Models and Technologies (SACMAT). 200
Nonmonotonic Trust Management for P2P Applications
Community decisions about access control in virtual communities are
non-monotonic in nature. This means that they cannot be expressed in current,
monotonic trust management languages such as the family of Role Based Trust
Management languages (RT). To solve this problem we propose RT-, which adds a
restricted form of negation to the standard RT language, thus admitting a
controlled form of non-monotonicity. The semantics of RT- is discussed and
presented in terms of the well-founded semantics for Logic Programs. Finally we
discuss how chain discovery can be accomplished for RT-.Comment: This paper appears in the proceedings of the 1st International
Workshop on Security and Trust Management (STM 2005). To appear in ENTC
A Calculus for Trust Management (talk)
Talk given at GC 2004: MyThS/MIKADO/DART Meeting, Venice 16.06.0
GEM: a Distributed Goal Evaluation Algorithm for Trust Management
Trust management is an approach to access control in distributed systems
where access decisions are based on policy statements issued by multiple
principals and stored in a distributed manner. In trust management, the policy
statements of a principal can refer to other principals' statements; thus, the
process of evaluating an access request (i.e., a goal) consists of finding a
"chain" of policy statements that allows the access to the requested resource.
Most existing goal evaluation algorithms for trust management either rely on a
centralized evaluation strategy, which consists of collecting all the relevant
policy statements in a single location (and therefore they do not guarantee the
confidentiality of intensional policies), or do not detect the termination of
the computation (i.e., when all the answers of a goal are computed). In this
paper we present GEM, a distributed goal evaluation algorithm for trust
management systems that relies on function-free logic programming for the
specification of policy statements. GEM detects termination in a completely
distributed way without disclosing intensional policies, thereby preserving
their confidentiality. We demonstrate that the algorithm terminates and is
sound and complete with respect to the standard semantics for logic programs.Comment: To appear in Theory and Practice of Logic Programming (TPLP
Trust Management Model for Cloud Computing Environment
Software as a service or (SaaS) is a new software development and deployment
paradigm over the cloud and offers Information Technology services dynamically
as "on-demand" basis over the internet. Trust is one of the fundamental
security concepts on storing and delivering such services. In general, trust
factors are integrated into such existent security frameworks in order to add a
security level to entities collaborations through the trust relationship.
However, deploying trust factor in the secured cloud environment are more
complex engineering task due to the existence of heterogeneous types of service
providers and consumers. In this paper, a formal trust management model has
been introduced to manage the trust and its properties for SaaS in cloud
computing environment. The model is capable to represent the direct trust,
recommended trust, reputation etc. formally. For the analysis of the trust
properties in the cloud environment, the proposed approach estimates the trust
value and uncertainty of each peer by computing decay function, number of
positive interactions, reputation factor and satisfaction level for the
collected information.Comment: 5 Pages, 2 Figures, Conferenc
A Distributed Context-Aware Trust Management Architecture
The realization of a pervasive context-aware service platform imposes new challenges for the security and privacy aspects of the system in relation to traditional service platforms. One important aspect is related with the management of trust relationships, which is especially hard in a pervasive environment because users are supposed to interact with entities unknown before hand in an ad-hoc and dynamic manner. Current trust management solutions do not adapt nor scale well in this dynamic service provisioning scenario because they require previously defined trust relationships in order to operate. The objective of this thesis is to design, prototype and validate a context-aware distributed trust management architecture in order to address: (a) the lack of integration between available trust solutions and security and privacy management languages, and (b) the dynamic characteristics of a context-aware service platform
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