Results 1 - 10
of
85
A Reputation-based Approach for Choosing Reliable Resources IN PEER-TO-PEER NETWORKS
- PROC. OF THE 9TH ACM CONFERENCE ON COMPUTER AND COMMUNICATIONS SECURITY (CCS
, 2002
"... ..."
(Show Context)
A Survey of Trust in Computer Science and the Semantic Web
, 2007
"... Trust is an integral component in many kinds of human interaction, allowing people to act under uncertainty and with the risk of negative consequences. For example, exchanging money for a service, giving access to your property, and choosing between conflicting sources of information all may utilize ..."
Abstract
-
Cited by 142 (3 self)
- Add to MetaCart
Trust is an integral component in many kinds of human interaction, allowing people to act under uncertainty and with the risk of negative consequences. For example, exchanging money for a service, giving access to your property, and choosing between conflicting sources of information all may utilize some form of trust. In computer science, trust is a widelyused term whose definition differs among researchers and application areas. Trust is an essential component of the vision for the Semantic Web, where both new problems and new applications of trust are being studied. This paper gives an overview of existing trust research in computer science and the Semantic Web.
Towards practical automated trust negotiation
- In Proceedings of the Third International Workshop on Policies for Distributed Systems and Networks (Policy 2002
, 2002
"... Exchange of attribute credentials is a means to establish mutual trust between strangers that wish to share resources or conduct business transactions. Automated Trust Negotiation (ATN) is an approach to regulate the exchange of sensitive credentials by using access control policies. Existing ATN wo ..."
Abstract
-
Cited by 106 (12 self)
- Add to MetaCart
(Show Context)
Exchange of attribute credentials is a means to establish mutual trust between strangers that wish to share resources or conduct business transactions. Automated Trust Negotiation (ATN) is an approach to regulate the exchange of sensitive credentials by using access control policies. Existing ATN work makes unrealistic simplifying assumptions about credential-representation languages and credential storage. Moreover, while existing work protects the transmission of credentials, it fails to hide the contents of credentials, thus providing uncontrolled access to potentially sensitive attributes. To protect information about sensitive attributes, we introduce the notion of attribute acknowledgment policies (Ack policies). We then introduce the trust target graph (TTG) protocol, which supports a more realistic credential language, Ack policies, and distributed storage of credentials. 1
A Unified Scheme for Resource Protection in Automated Trust Negotiation
- In IEEE Symposium on Security and Privacy
, 2003
"... Automated trust negotiation is an approach to establishing trust between strangers through iterative disclosure of digital credentials. In automated trust negotiation, access control policies play a key role in protecting resources from unauthorized access. Unlike in traditional trust management sys ..."
Abstract
-
Cited by 90 (2 self)
- Add to MetaCart
(Show Context)
Automated trust negotiation is an approach to establishing trust between strangers through iterative disclosure of digital credentials. In automated trust negotiation, access control policies play a key role in protecting resources from unauthorized access. Unlike in traditional trust management systems, the access control policy for a resource is usually unknown to the party requesting access to the resource, when trust negotiation starts. The negotiating parties can rely on policy disclosures to learn each other's access control requirements. However, a policy itself may also contain sensitive information. Disclosing policies' contents unconditionally may leak valuable business information or jeopardize individuals' privacy. In this paper, we propose UniPro, a unified scheme to model protection of resources, including policies, in trust negotiation. UniPro improves on previous work by modeling policies as first-class resources, protecting them in the same way as other resources, providing fine-grained control over policy disclosure, and clearly distinguishing between policy disclosure and policy satisfaction, which gives users more flexibility in expressing their authorization requirements. We also show that UniPro can be used with practical negotiation strategies without jeopardizing autonomy in the choice of strategy, and present criteria under which negotiations using UniPro are guaranteed to succeed in establishing trust.
Requirements for policy languages for trust negotiation
- In 3rd International Workshop on Policies for Distributed Systems and Networks
, 2002
"... In open systems like the Internet, traditional approaches to security based on identity do not provide a solution to the problem of establishing trust between strangers, because strangers do not share the same security domain. A new approach to establishing trust between strangers is trust negotiati ..."
Abstract
-
Cited by 81 (8 self)
- Add to MetaCart
(Show Context)
In open systems like the Internet, traditional approaches to security based on identity do not provide a solution to the problem of establishing trust between strangers, because strangers do not share the same security domain. A new approach to establishing trust between strangers is trust negotiation, the bilateral exchange of digital credentials describing attributes of the negotiation participants. This approach relies on access control policies that govern access to protected resources by specifying credential combinations that must be submitted to obtain authorization. In this paper we describe a model for trust negotiation, focusing on the central role of policies. We delineate requirements for policy languages and runtime systems for trust negotiation, and evaluate four existing policy languages for trust management with respect to those requirements. We conclude with recommendations for extending existing policy languages or developing new policy languages to make them suitable for use in future trust negotiation systems. 1.
A logic-based framework for attribute based access control
- In Workshop on Formal Methods in Security Engineering
, 2004
"... Attribute based access control (ABAC) grants accesses to services based on the attributes possessed by the requester. Thus, ABAC differs from the traditional discretionary ac-cess control model by replacing the subject by a set of at-tributes and the object by a set of services in the access control ..."
Abstract
-
Cited by 71 (3 self)
- Add to MetaCart
Attribute based access control (ABAC) grants accesses to services based on the attributes possessed by the requester. Thus, ABAC differs from the traditional discretionary ac-cess control model by replacing the subject by a set of at-tributes and the object by a set of services in the access control matrix. The former is appropriate in an identity-less system like the Internet where subjects are identified by their characteristics, such as those substantiated by certifi-cates. These can be modeled as attribute sets. The latter is appropriate because most Internet users are not privy to method names residing on remote servers. These can be modeled as sets of service options. We present a frame-work that models this aspect of access control using logic programming with set constraints of a computable set the-ory [DPPR00]. Our framework specifies policies as stratified constraint flounder-free logic programs that admit primitive recursion. The design of the policy specification framework ensures that they are consistent and complete. Our ABAC policies can be transformed to ensure faster runtimes.
Protecting Privacy during On-line Trust Negotiation
- In 2nd Workshop on Privacy Enhancing Technologies
, 2002
"... The dramatic growth of services and information on the Internet is accompanied by growing concerns over privacy. Trust negotiation is a new approach to establishing trust between strangers on the Internet through the bilateral exchange of digital credentials, the on-line analogue to the paper cr ..."
Abstract
-
Cited by 54 (5 self)
- Add to MetaCart
(Show Context)
The dramatic growth of services and information on the Internet is accompanied by growing concerns over privacy. Trust negotiation is a new approach to establishing trust between strangers on the Internet through the bilateral exchange of digital credentials, the on-line analogue to the paper credentials people carry in their wallets today. When a credential contains sensitive information, its disclosure is governed by an access control policy that specifies credentials that must be received before the sensitive credential is disclosed. This paper identifies the privacy vulnerabilities present in on-line trust negotiation and the approaches that can be taken to eliminate or minimize them. The paper proposes modifications to negotiation strategies to help prevent the inadvertent disclosure of credential information during on-line trust negotiation for those credentials or credential attributes that have been designated as sensitive, private information.
Managing and sharing servents’ reputations in P2P systems
- IEEE Transactions on Data and Knowledge Engineering
, 2003
"... Peer-to-peer information sharing environments are increasingly gaining acceptance on the Internet as they provide an infrastructure in which the desired information can be located and downloaded while preserving the anonymity of both requestors and providers. As recent experience with P2P environmen ..."
Abstract
-
Cited by 44 (8 self)
- Add to MetaCart
Peer-to-peer information sharing environments are increasingly gaining acceptance on the Internet as they provide an infrastructure in which the desired information can be located and downloaded while preserving the anonymity of both requestors and providers. As recent experience with P2P environments such as Gnutella shows, anonymity opens the door to possible misuses and abuses by resource providers exploiting the network as a way to spread tampered-with resources, including malicious programs, such as Trojan Horses and viruses. In this paper, we propose an approach to P2P security where servents can keep track, and share with others, information about the reputation of their peers. Reputation sharing is based on a distributed polling algorithm by which resource requestors can assess the reliability of perspective providers before initiating the download. The approach complements existing P2P protocols and has a limited impact on current implementations. Furthermore, it keeps the current level of anonymity of requestors and providers, as well as that of the parties sharing their view on others’ reputations.
Protecting Sensitive Attributes in Automated Trust Negotiation
- In ACM Workshop on Privacy in the Electronic Society
, 2002
"... Exchange of attribute credentials is a means to establish mutual trust between strangers that wish to share resources or conduct business transactions. Automated Trust Negotiation (ATN) is an approach to regulate the flow of sensitive attributes during such an exchange. Recently, it has been noted t ..."
Abstract
-
Cited by 38 (7 self)
- Add to MetaCart
(Show Context)
Exchange of attribute credentials is a means to establish mutual trust between strangers that wish to share resources or conduct business transactions. Automated Trust Negotiation (ATN) is an approach to regulate the flow of sensitive attributes during such an exchange. Recently, it has been noted that early ATN designs do not adequately protect the privacy of negotiating parties. While unauthorized access to credentials can be denied, sensitive information about the attributes they carry may easily be inferred based on the behavior of negotiators faithfully adhering to proposed negotiation procedure. Some proposals for correcting this problem do so by sacrificing the ability to e#ectively use sensitive credentials. We study an alternative design that avoids this pitfall by allowing negotiators to define policy protecting the attribute itself, rather than the credentials that prove it. We show how such a policy can be enforced. We address technical issues with doing this in the context of trust management-style credentials, which carry delegations and enable one attribute to be inferred from others, and in the context where credentials are stored in a distributed way, and must be discovered and collected before being used in ATN.
Secure Context-sensitive Authorization
- Journal of Pervasive and Mobile Computing
, 2005
"... There is a recent trend toward rule-based authorization systems to achieve flexible security policies. Also, new sensing technologies in pervasive computing make it possible to define context-sensitive rules, such as “allow database access only to staff who are currently located in the main office. ..."
Abstract
-
Cited by 35 (6 self)
- Add to MetaCart
There is a recent trend toward rule-based authorization systems to achieve flexible security policies. Also, new sensing technologies in pervasive computing make it possible to define context-sensitive rules, such as “allow database access only to staff who are currently located in the main office. ” However, these rules, or the facts that are needed to verify authority, often involve sensitive context information. This paper presents a secure context-sensitive authorization system that protects confidential information in facts or rules. Furthermore, our system allows multiple hosts in a distributed environment to perform the evaluation of an authorization query in a collaborative way; we do not need a universally trusted central host that maintains all the context information. The core of our approach is to decompose a proof for making an authorization decision into a set of sub-proofs produced on multiple different hosts, while preserving the integrity and confidentiality policies of the mutually untrusted principals operating these hosts. We prove the correctness of our algorithm. 1
