Effective representation of RT-LOTOS terms by finite time petri nets

The paper describes a transformational approach for the specification and formal verification of concurrent and real-time systems. At upper level, one system is specified using the timed process algebra RT-LOTOS. The output of the proposed transformation is a Time Petri net (TPN). The paper particularly shows how a TPN can be automatically constructed from an RT-LOTOS specification using a compositionally defined mapping. The proof of the translation consistency is sketched in the paper and developed in [1]. The RT-LOTOS to TPN translation patterns formalized in the paper are being implemented. in a prototype tool. This enables reusing TPNs verification techniques and tools for the profit of RT-LOTOS

Fair On-line Auctions Without Special Trusted Parties

. Traditional face-to-face (English) auctions rely on the auctioneer to fairly interact with bidders to accept the highest bid on behalf of the seller. On-line auctions also require fair negotiation. However, unlike face-to-face auctions, on-line auctions are inherently subject to attacks because the bidders and auctioneer are not copresent. These attacks include selectively blocking bids based on the bidder and amount and selectively closing the auction after a particular bid is received. In this paper, we present an on-line English auction in which bids are processed fairly and the auction closes fairly without specialized trusted parties. In particular, there is no need to trust the auctioneer to obtain a fair outcome to the auction. 1 Introduction The number of on-line auctions is rapidly growing. In fact, forecasts indicate that on-line auctions and barter will generally replace conventional purchase of set-price items in the future [4]. Currently, there are nearly one hundred on..

Trust in Anonymity Networks

Anonymity is a security property of paramount importance, as we move steadily towards a wired, online community. Its import touches upon subjects as different as eGovernance, eBusiness and eLeisure, as well as personal freedom of speech in authoritarian societies. Trust metrics are used in anonymity networks to support and enhance reliability in the absence of verifiable identities, and a variety of security attacks currently focus on degrading a user's trustworthiness in the eyes of the other users. In this paper, we analyse the privacy guarantees of the \textsc{Crowds} anonymity protocol, with and without onion forwarding, for standard and adaptive attacks against the trust level of honest users

Vol13#3_Advocates for Hawaii's Children

Delivery of products bought online can violate consumers' privacy, although not in a straightforward way. In particular, delivery companies that have contracted with a website know the company selling the product, as well as the name and address of the online customer. To make matters worse, if the same delivery company has contracted with many websites, aggregated information per address may be used to profile customers' transaction activities. In this paper, we present a fair delivery service system with guaranteed customer anonymity and merchant-customer unlinkability, with reasonable assumptions about the threat model