As elements that constitute electronic procurement systems, anonymous auction, object delivery, and object monitoring systems are developed based on ITLs, anonymous tags and anonymous memories, respectively. The developed anonymous auction system enables entities to securely sell and/or buy their articles without disclosing their identities, and the anonymous object delivery system enables them to send or receive their articles to or from other entities also without disclosing their identities. The object monitoring system monitors running states of objects (e.g. home appliances) so that they can be used efficiently, safely, and environmentally friendlily while preserving privacies of their users. It also detects dishonest users (e.g. that discords their objects illegitimately) without invading privacies of honest users. Here, anonymous memories used in the monitoring system are memory sections by which users can securely and efficiently maintain their data without disclosing their identities.
TopIntroduction
In this chapter, auction, object delivery and object monitoring systems are developed as components of electronic procurement (e-procurement) systems, in which people connected by networks sell or buy articles, transportation service providers deliver articles to their buyers, and monitoring stations remotely monitor running states of articles such as home appliances to enable individual users to use them efficiently, safely, and environmentally friendlily. Here, although this kind of e-procurement systems not only make our societies efficient, convenient and safe but also enable effective and efficient recycling of products and materials, to encourage more people to accept these systems, privacies of individual sellers, buyers or users involved must be preserved. Therefore, anonymous e-procurement systems supported by security and service components discussed in Section 2 play important roles.
Figure 1 depicts the overall configuration of the anonymous e-procurement system (Tamura, 2008). In the figure, participants sell or buy articles to or from other participants, and among the participants, some of them sell or buy articles without disclosing their identities and in these cases payments are carried out through anonymous credit card systems discussed in the previous chapter, but some others (e.g. established manufacturers) sell or buy articles while disclosing their exact identities. Here, an anonymous auction mechanism is one of schemes in which people sell and buy articles without disclosing their identities. Then once articles are bought by buyers, buyers e.g. auction winners, receive articles through anonymous object delivery systems from sellers (they may be also anonymous) without disclosing their identities, and monitoring stations monitor running states of articles such as home appliances while preserving privacies of their owners or users. When monitoring stations detect that the articles are used inadequately they warn the anonymous users of the dangers, or when the articles are discarded illegitimately they identify the liable users without invading any privacy of other users.
Figure 1. Configuration of anonymous e-procurement system
TopAnonymous Auction Systems
Although there are many kinds of auction protocols this section discusses 2 of them i.e. English and Vickrey auction schemes (Yokoo, 2006). Both English and Vickrey auction schemes consist of sellers S1, S2, ---, SM, buyers B1, B2, ---, BN, auctioneer A and BBs (bulletin boards) as shown in Figure 2. In the figure, each seller Sj brings its article to auctioneer A, A conducts auctions, in which buyers B1, B2, ---, BN bid prices to buy the article brought by Sj, and auction results and if necessary states of the auction processes are disclosed in BBs. Here, when auctions are anonymous each Bh can make bids and pay for its winning articles without disclosing its identity to others including auctioneer A and seller Sj that had brought the article. Also, each seller Sj can bring its articles and be paid for them while concealing its identity from others. Here, anonymous networks enable sellers and buyers to access the auction system without disclosing their identities, anonymous credit card systems enable anonymous buyers and sellers to conduct their payment processes, and anonymous object delivery systems enable sellers and buyers to bring their owning articles and to receive their winning articles without disclosing their identities to others.