Trusted third party

About: Trusted third party is a research topic. Over the lifetime, 2919 publications have been published within this topic receiving 60935 citations.

Gradual trust and distrust in recommender systems

Abstract: Trust networks among users of a recommender system (RS) prove beneficial to the quality and amount of the recommendations. Since trust is often a gradual phenomenon, fuzzy relations are the pre-eminent tools for modeling such networks. However, as current trust-enhanced RSs do not work with the notion of distrust, they cannot differentiate unknown users from malicious users, nor represent inconsistency. These are serious drawbacks in large networks where many users are unknown to each other and might provide contradictory information. In this paper, we advocate the use of a trust model in which trust scores are (trust,distrust)-couples, drawn from a bilattice that preserves valuable trust provenance information including gradual trust, distrust, ignorance, and inconsistency. We pay particular attention to deriving trust information through a trusted third party, which becomes especially challenging when also distrust is involved.

Single one-time password token with single PIN for access to multiple providers

Abstract: A system and a method are disclosed that includes a first party with a terminal and a one-time password token, one or more second parties, each with a host application system and a service provider authentication server, and a third party with a host application system and a master authentication server. The first party uses a single one-time password token with a single personal identification number (PIN) to access the one or more second parties. A third party issues the token to the first party and synchronizes token secrets and parameters with the one or more second parties. This offloads token management from the second parties and allows the second parties to directly authenticate the first party. The authentication of the first party by the second party does not involve the third party.

An efficient non-repudiation protocol

Abstract: Fairness may be a desirable property of a non-repudiation service. Protocols can achieve fairness through the involvement of a trusted third party but the extent of the trusted third party's involvement can vary between protocols. Hence, one of the goals of designing an efficient non-repudiation protocol is to reduce the workload of the trusted third party. In this paper, we present a variant of our fair non-repudiation protocol (1996), where the trusted third party is involved only in the case that one party cannot obtain the expected non-repudiation evidence from the other party. This variant is efficient in an environment where the two parties are likely to resolve communications problems between themselves.

Computer-based method and apparatus for interactive computer-assisted negotiations

Abstract: A computer-based method and apparatus for interactive computer-assisted negotiations assists multiple parties involved in complex multiple issue negotiations in reaching an agreement that optimizes both the individual and overall benefit to the parties. Each of the parties to a conflict or dispute to be negotiated enters their preferences concerning each issue of the conflict into a computer system. If desired, each party to the dispute can have a separate computer system so that each party's preference information remains confidential to that party. The preference information includes data on satisfaction functions for each of the issues which defines a party's relative level of satisfaction as a function of a numerical value for the outcome of that issue. Each party may also enter one or more proposed alternative agreements which provide the party with a specified level of satisfaction. Using standard mixed integer linear programming techniques, the preference information is employed to solve an optimization problem in which an alternative agreement, known as the common base if accepted by all parties, is first generated that provides at least the same level of satisfaction to each party that their own proposal provides, while at the same time minimizing the maximum gain and satisfaction achieved by any party between their proposal and the generated alternative agreement. Next, an optimal agreement to the conflict is determined, again using linear programming techniques, by maximizing the minimum gain in satisfaction achieved by each of the parties in going from the common base to the improved alternative. This will, at the same time, maximize the overall benefit to all of the parties. For maximum security of all party's confidential information, a separate computer system located at a neutral site can be connected to each individual party's computer system. In this case, alternatives are generated at the neutral site and transmitted back to each party's own computer system.

PPFA: Privacy Preserving Fog-Enabled Aggregation in Smart Grid

Abstract: For constrained end devices in Internet of Things, such as smart meters (SMs), data transmission is an energy-consuming operation. To address this problem, we propose an efficient and privacy-preserving aggregation system with the aid of Fog computing architecture, named PPFA , which enables the intermediate Fog nodes to periodically collect data from nearby SMs and accurately derive aggregate statistics as the fine-grained Fog level aggregation. The Cloud/utility supplier computes overall aggregate statistics by aggregating Fog level aggregation. To minimize the privacy leakage and mitigate the utility loss, we use more efficient and concentrated Gaussian mechanism to distribute noise generation among parties, thus offering provable differential privacy guarantees of the aggregate statistic on both Fog level and Cloud level. In addition, to ensure aggregator obliviousness and system robustness, we put forward a two-layer encryption scheme: the first layer applies OTP to encrypt individual noisy measurement to achieve aggregator obliviousness, while the second layer uses public-key cryptography for authentication purpose. Our scheme is simple, efficient, and practical, it requires only one round of data exchange among a SM, its connected Fog node and the Cloud if there are no node failures, otherwise, one extra round is needed between a meter, its connected Fog node, and the trusted third party.