Implementation of Multifactor Authentication Using Optimistic Fair Exchange

In this work, two participants fairly send or receive things through the aid of intermediate who is only engaged if required. An up-to-date accepted necessity is with the aim of involving third party in the trade should be transparent, to save from privacy and evade terrible publicity. Together, a dishonest intermediate will negotiate the fairness of the trade and so the intermediate should be liable in case of any behavioural changes. Optimistic fair exchange (OFE) is one of the classical protocols to assure fairness of indulgence for a party. This exchange can be done by means of an arbitrator. The most important aspect of OFE is to describe security models so as to capture real-time attacks and design schemes secure in practical models. Signaller is confirmed with the data to send the correct person to address that to make sure it is. Since then the SMS has gone through to achieve that can hold the path to the right to see which if any is the fact that to ensure there is. After the signature is created by creating it to be able to well take care of it and then to the right of the person to pay off that is sure to make it. In this project, to avoid the third party attack (hacking) and unauthorized person access the particular important data. The data should be transmitted in sender to receiver that receiver only have a correct data without any data losses, protect a data security in cyber-attacks. A signature may be digitally and OFE design for the exchanged item have trade-off between transparency and accountability.

Optimistic Fair Exchange in Cloud-Assisted Cyber-Physical Systems

Recently, optimistic fair exchange in electronic commerce (e-commerce) or mobile commerce (m-commerce) has made great progress. However, new technologies create large amounts of data and it is difficult to handle them. Fortunately, with the assistance of cloud computing and big data, optimistic fair exchange of digital items in cyber-physical systems (CPSes) can be efficiently managed. Optimistic fair exchange in cloud-assisted CPSes mainly focuses on online data exchange in e-commerce or online contracts signing. However, there exist new forms of risks in the uncertain network environment. To solve the above problems, we use a new technique called verifiably encrypted identity-based signature (VEIS) to construct optimistic fair exchange in cloud-assisted CPSes. VEIS is an encrypted signature, and we can check the validity of the underlying signature without decrypting it. We introduce a robust arbitration mechanism to guarantee fairness of the exchange, and even the trusted third party (TTP) cannot get the original signatures of the exchange parties. And the TTP in our protocol is offline, which greatly improves the efficiency. Besides, we show that our protocol is secure, fair, and practical.

A Generic Framework for Accountable Optimistic Fair Exchange Protocol

Optimistic Fair Exchange protocol was designed for two parties to exchange in a fair way where an arbitrator always remains offline and will be referred only if any dispute happens. There are various optimistic fair exchange protocols with different security properties in the literature. Most of the optimistic fair exchange protocols satisfy resolution ambiguity where a signature signed by the signer is computational indistinguishable from the one resolved by the arbitrator. Huang et al. proposed the first generic framework for accountable optimistic fair exchange protocol in the random oracle model where it possesses resolution ambiguity and is able to reveal the actual signer when needed. Ganjavi et al. later proposed the first generic framework in the standard model. In this paper, we propose a new generic framework for accountable optimistic fair exchange protocol in the standard model using ordinary signature, convertible undeniable signature, and ring signature scheme as the underlying building blocks. We also provide an instantiation using our proposed generic framework to obtain an efficient pairing-based accountable optimistic fair exchange protocol with short signature.