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.

Understanding Stakeholders Needs for Using Blockchain Based Smart Contracts in Construction Industry of Thailand: Extended TAM Framework

Abstract: Traditionally, the contractual transactions between untrusted parties were generally carried out in a centralized form, requiring a trusted third party to act as a witness, and make them legally binding, enforceable and trustful. However, the process of involving a third party is associated with high expenses and delays. The Blockchain technology has been developed to address these issues, by allowing parties to enter into contractual agreements without involvement of third parties. The contract allows conducting of trusted agreements and transactions between unknown parties without the need of having an enforcement mechanism, trusted third party or legal system. In the construction sector, the smart contracts would help eliminate the slow, expensive and brittle transactions, associated with integrity and transparency issues due to potential records manipulation of the traditional contracts. This study focused on designing a blockchain smart contract adoption model and understanding stakeholders' needs for using blockchain-based smart contracts in construction industry. The study proposed the extended Technology Acceptance Model, which illustrates the constructs around the adoption and use of the blockchain smart contracts in Thailand construction sector. The model suggests that factor such as perceived financial costs, facilitating conditions, trust and readiness has influence on the construct of perceived usefulness (PU) and perceived ease of use (PEOU), which affects the behavioral intention to use the blockchain smart contracts in construction industry of Thailand.

Im)possibility of safe exchange mechanism design

Abstract: Safe exchange is a key issue in multiagent systems, especially in electronic transactions where nondelivery is a major problem. In this paper we present a unified framework for modeling safe exchange mechanisms. It captures the disparate earlier approaches as well as new safe exchange mechanisms (e.g., reputation, locking). Being an overarching framework, it also allows us to study what is inherently possible and impossible in safe exchange. We study this under different game-theoretic solution concepts, with and without a trusted third party, and with an offline third party that only gets involved if the exchange fails. The results vary based on the generality of the exchange setting, the existence (or creative construction) of special types of items to be exchanged, and the magnitude of transfer costs, defection costs, and escrow fees. Finally, we present an incentive-compatible negotiation protocol for selecting the best safe exchange mechanism when the agents do not know each others' costs for the different alternatives.

Towards Multiple-Payment Schemes for Digital Money

Abstract: Recently, many payment schemes for digital money have been proposed. In most of these schemes money can be spent only once and must then immediately be returned to the bank. The purpose of this paper is to show the advantages of a scheme which allows the recipient of the money to use it directly for further purchases. We discuss why most existing schemes do not support such a payment scheme and make a proposal of how to overcome this drawback. Furthermore, we address the problem of achieving a fair exchange of money against service between the customer and the vendor. Few solutions to this problem have been published and all involve a trusted third party which actively supports the exchange. Using such a trustee has the disadvantage that — for high transaction rates — he easily constitutes a bottleneck. We present an alternative solution based on a `passive' trustee thereby avoiding the former disadvantage.

A New Certificateless Electronic Cash Scheme with Multiple Banks Based on Group Signatures

Abstract: Most of the proposed E-cash systems require that the shop and customer belong to the same bank, which becomes the bottle-neck of E-cashpsilas wide application. Fangguo Zhang et al. proposed a model of electronic cash using multi-banks, but a trusted third party is needed in their system. To solve this problem, we propose a new electronic cash scheme based on group signature from bilinear pairings. In the new scheme, the shop and customer need not belong to the same bank, and a trusted third party is not needed. The identity based public key cryptosystem is used, the KGC (key generator center, or central bank) can only control partial private key of the customer, the customer known all private key of himself, so the private key escrow problem in the identity based public key cryptosystem is solved in the system. As the scheme is certificateless, the management and maintenance of the public key is much simplified.