Trust management (original) (raw)

Balancing Trust and Risk in Access Control

The increasing availability of large and diverse datasets (big data) calls for increased flexibility in access control so to improve the exploitation of the data. Risk-aware access control systems offer a natural approach to the problem. We propose a novel access control framework that combines trust with risk and supports access control in dynamic contexts through trust enhancement mechanisms and risk mitigation strategies. This allows to strike a balance between the risk associated with a data request and the trustworthiness of the requester. If the risk is too large compared to the trust level, then the framework can identify adaptive strategies leading to a decrease of the risk (e.g., by remov-ing/obfuscation part of the data through anonymization) or to increase the trust level (e.g., by asking for additional obligation to the requester). We outline a modular architecture to realize our model, and we describe how these strategies can be actually realized in a realistic use case.

TrustBAC: integrating trust relationships into the RBAC model for access control in open systems

… of the eleventh ACM symposium on Access …, 2006

Conventional access control models like role based access control are suitable for regulating access to resources by known users. However, these models have often found to be inadequate for open and decentralized multi-centric systems where the user population is dynamic and the identity of all users are not known in advance. For such systems, credential based access control has been proposed. Credential based systems achieve access control by implementing a binary notion of trust. If a user is trusted by virtue of successful evaluation of its credentials it is allowed access, otherwise not. However, such credential based models have also been found to be lacking because of certain inherent drawbacks with the notion of credentials. In this work, we propose a trust based access control model called TrustBAC. It extends the conventional role based access control model with the notion of trust levels. Users are assigned to trust levels instead of roles based on a number of factors like user credentials, user behavior history, user recommendation etc. Trust levels are assigned to roles which are assigned to permissions as in role based access control. The TrustBAC model thus incorporates the advantages of both the role based access control model and credential based access control models.

Trust-orBAC: A Trust Access Control Model in Multi-Organization Environments

Lecture Notes in Computer Science, 2012

Access control in Multi-Organization Environment is a critical issue. Classical access control models like Role Based Access Control (RBAC) and Organization Based Access Control (ORBAC) need some improvements to be used in such environment, where the collaboration is established between organizations and not directly with the clients. In particular, some characteristics of this scenario are that the users may be unknown in advance and/or the behaviors of the users and the organization may change during the collaboration. Hence, in this context the use of trust management with an access control model is recommended. To achieve this goal in this paper a new model called TR U S T-ORBAC that adds the notion of trust management to ORBAC is presented. This approach consists in defining two dynamic trust vectors: one for the organizations and one for users which are based on different parameters such as knowledge, reputation and experience. Finally, we illustrate the use of TR U S T-ORBAC with a case study.

Trust management services in relational databases

Proceedings of the 2nd ACM symposium on Information, computer and communications security, 2007

Trust management represents today a promising approach for supporting access control in open environments. While several approaches have been proposed for trust management and significant steps have been made in this direction, a major obstacle that still exists in the realization of the benefits of this paradigm is represented by the lack of adequate support in the DBMS. In this paper, we present a design that can be used to implement trust management within current relational DBMSs. We propose a trust model with a SQL syntax and illustrate the main issues arising in the implementation of the model in a relational DBMS. Specific attention is paid to the efficient verification of a delegation path for certificates. This effort permits a relatively inexpensive realization of the services of an advanced trust management model within current relational DBMSs.

Trust Models for Access Control

This paper using the concept of a trust model aims at providing practical value to distributed security. It describes a method to derive authentication and authorisation requirements from the reduction of trust inherently associated with the number of participating entities placed in a communication path between two parties. It demonstrates how a traditional approach to understanding the trust relationships between interacting entities can be applied directly to the definition and design of secure e-business architectures. By applying these principles, the business and social impact of a security architecture which optimizes the provided level of security, performance of the architecture and the investment associated with that security architecture can be realized.

A Trust-Based Model for Information Integrity in Open Systems

IFIP International Federation for Information Processing, 2005

While it is difficult to apply conventional security services to a system without a central authority, trust management offers a solution for information assurance in such a system. In this paper, we have developed a policyoriented decision model based on object trust management to assist users in selecting reliable and secure information in an open system. In the proposed model, an object represents a topic or issue under discussion, and it may have multiple versions, each of which represents a subject's opinion towards the characteristics of that object. The developed trust-based decision model assists a user to select one object version with desired level of quality and security features from available versions of a given object. The model balances both positive and negative aspects of an object version, and an evaluator can explicitly specify, in form of a policy specification, which features of an object version are not acceptable and which features are favorable. A high-level policy language, called Selector, expresses the policy specification in an unambiguous way. Selector consists of primary and residual policy statements. It supports recursive function calls, and the invoked external functions are defined separately from the language itself. The proposed decision model doesn't guarantee to select the "best" version for a given object. Rather it ensures that the selected version meets a user's requirement for information integrity.

Access control and trust in the use of widely distributed services

Software: Practice and Experience, 2003

OASIS is a role-based access control architecture for achieving secure interoperation of independently managed services in an open, distributed environment. OASIS differs from other RBAC schemes in a number of ways: role management is decentralised, roles are parametrised, and privileges are not delegated. OASIS depends on an active middleware platform to notify services of any relevant changes in their environment. Services define roles and establish formally specified policy for role activation and service use; users must present the required credentials and satisfy specified constraints in order to activate a role or invoke a service. The membership rule of a role indicates which of the role activation conditions must remain true while the role is active. A role is deactivated immediately if any of the conditions of the membership rule associated with its activation become false. Instead of privilege delegation OASIS introduces the notion of appointment, whereby being active in certain roles carries the privilege of issuing appointment certificates to other users. Appointment certificates capture the notion of long lived credentials such as academic and professional qualification or membership of an organisation. The role activation conditions of a service may include appointment certificates, prerequisite roles and environmental constraints. We define the model and architecture and discuss engineering details, including security issues. We illustrate how an OASIS session can span multiple domains, and discuss how it can be used in a global environment where roving principals, in possession of appointment certificates, encounter and wish to use services. We propose a minimal infrastructure to enable widely distributed, independently developed services to enter into agreements to respect each other's credentials. We speculate on a further extension to mutually unknown, and therefore untrusted, parties. Each party will accumulate audit certificates which embody its interaction history and which may form the basis of a web of trust.

QuanTM: A Quantitative Trust Management system

Proceedings of the 2nd European Workshop on System Security, EUROSEC'09, 2009

Quantitative Trust Management (QTM) provides a dynamic interpretation of authorization policies for access control decisions based on upon evolving reputations of the entities involved. QuanTM, a QTM system, selectively combines elements from trust management and reputation management to create a novel method for policy evaluation. Trust management, while effective in managing access with delegated credentials (as in PolicyMaker and KeyNote), needs greater flexibility in handling situations of partial trust. Reputation management provides a means to quantify trust, but lacks delegation and policy enforcement. This paper reports on QuanTM's design decisions and novel policy evaluation procedure. A representation of quantified trust relationships, the trust dependency graph, and a sample QuanTM application specific to the KeyNote trust management language, are also proposed.

Modeling access control and user actions using trust - based access control policies

2020

This paper is a natural continuation of previous research on the implementation of confidentiality in small, medium, and virtual enterprises. This research began in 2009, with the work "Xml Based Techniques for Data Privacy in E-Business" which revealed that for small, medium, and virtual enterprises that often represent start-ups, trust is a basic element. Thus, in 2010, we published the paper "Control access to information by applying policies based on trust hierarchies". Present work shows a method of modeling the hierarchies of trust in computer systems. After a review of previous research and the presentation of the necessary conditions for accessing and applying actions on an object, published in "Data security management applying trust policies for small organizations, ad hoc organizations and virtual organizations" in 2012, this paper presents the four necessary steps, from the analysis of the manual system necessary to be automated to the deter...