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.

RAC: A Freerider-Resilient, Scalable, Anonymous Communication Protocol

Abstract: Enabling anonymous communication over the Internet is crucial. The first protocols that have been devised for anonymous communication are subject to freeriding. Recent protocols have thus been proposed to deal with this issue. However, these protocols do not scale to large systems, and some of them further assume the existence of trusted servers. In this paper, we present RAC, the first anonymous communication protocol that tolerates freeriders and that scales to large systems. Scalability comes from the fact that the complexity of RAC in terms of the number of message exchanges is independent from the number of nodes in the system. Another important aspect of RAC is that it does not rely on any trusted third party. We theoretically prove, using game theory, that our protocol is a Nash equilibrium, i.e, that freeriders have no interest in deviating from the protocol. Further, we experimentally evaluate RAC using simulations. Our evaluation shows that, whatever the size of the system (up to 100.000 nodes), the nodes participating in the system observe the same throughput.

An incentive mechanism for K-anonymity in LBS privacy protection based on credit mechanism

Abstract: In the location-based service (LBS) privacy protection, the most common and classic solution is K-anonymity, however, existing schemes rarely consider the issue that whether other mobile users are willing to provide assistance to the requesters to form the K-anonymity set, thus leading to their poor practicability. In this paper, an incentive mechanism based on credit is introduced into the distributed K-anonymity, and only providing assistance to the others, a user can gain and accumulate his credit. Based on the fuzzy logic in the soft computing, a probability threshold is introduced to reflect a user’s reputation, and only when a user’s reputation reaches this threshold, can he get the assistance from other neighbors. Security analysis shows that our scheme is secure with respect to various typical attacks. And because of not relying on a trusted third party, our scheme can avoid the security issue resulting from its breach. Extensive experiments indicate that the time to form the anonymity set is short and it increases slowly as the value of K increases. Finally, the additional traffic introduced by this scheme is very limited.

System and method for fair exchange of time-independent information goods over a network

Abstract: A system and method facilitates a fair exchange of time-independent information goods between a first party's computer and a second party's computer over a network, such as the Internet. The first party's computer creates a digital contract proposal concerning the exchange of information goods. The first party's computer digitally signs the contract proposal and stipulates a condition which, when satisfied by the second party, will create a valid contract. The first party's computer then transmits the signed contract proposal over the network to the second party's computer. The second party has one of two options: (1) satisfy the condition in the contract proposal to create a valid contract and return the valid contract to the first party, or (2) store the signed contract proposal without satisfying the condition and supply the information goods to the first party. Upon receipt of the contract or goods from the second party, the first party's computer supplies its information goods to the second party's computer. In the event that either party reneges, the non-reneging party can produce the valid contract and submit it to an adjudicator for enforcement and remedy.

System for secure transactions

Abstract: A multimedia network (1) with connected customer stations (2), merchant servers (3), and a payment server (5). Secure electronic transactions are performed using a secure electronic transactions protocol (SET), including exchange of digital certificates, managed by a Trusted Third Party Server (9). The customer stations comprise transactions management means (10), fit for performing said SET protocol and for managing said certificates for the customer station. A remote customer agent (13) represents the customer station in the negotiation and payment process. The customer station (2) comprises an agent interface (12), fit for transmission of codes, parameters and certificates between the customer agent (13) and the transactions management means (10). A remote merchant agent (14) represents the merchant station (3) in the negotiation and payment process with the customer agent (13) or the customer station (3), to have paid for the selected products in a secure way, under control of SET protocol.

Towards Reference Architecture for Cryptocurrencies: Bitcoin Architectural Analysis

Abstract: Bit coin is a new protocol with a potential to revolutionize financial system. Bit coin has a complex structure, where several interacting components build a peer-to-peer currency and a payment system without relying on any trusted third party. Bit coin is continually improved by an open source community, and various Bit coin libraries, APIs, and alternative implementations are being developed. Nevertheless, there is no up-to-date protocol specification or architecture description since the official whitepaper was published back in 2008. In this paper, we provide an up-to-date protocol specification and architectural analysis of the Bit coin system. We perform this analysis as the first step towards specification of the crypto currency reference architecture. The future reference architecture will serve as a starting architectural point for the development of new systems that leverage Bit coin protocol in different contexts and for various purposes. We also discuss whether the current architecture satisfies the system's primary purpose, i.e., Providing a pure decentralized version of the crypto currency.