This paper presents applications for the weak protection of secrets in which weakness is not just acceptable but desirable. For one application, two versions of a lottery scheme are presented in which the result of the lottery is determined by the ticket numbers purchased, but no one can control the outcome or determine what it is until after the lottery closes. This is because the outcome is k...

Fairness in document exchange has been well studied, while anonymity in the exchange, which protects the privacy of personal information such as identities and locations, has been either ignored or handled with partial or inappropriate considerations. In this paper we propose a new protocol for anonymous and fair document exchange between two parties with the assistance of an off-line trusted t...

We propose a new efficient protocol, which allows a pair of potentially mistrusting parties to exchange digital signatures over the Internet in a fair way, such that after the protocol is running, either each party obtains the other’s signature, or neither of them does. The protocol relies on an off-line Trusted Third Party (TTP), which does not take part in the exchange unless any of the parti...

In this paper, we propose a comparison of two seemingly similar problems, i.e., secure multiparty computation and fair exchange. However, if these two problems appear to bear a lot in common, they come from fields that differ greatly in the way the problems are described and approached, i.e., the fields of modern cryptography and distributed systems respectively. In that regard, straightforward...

Fair exchange protocols play an important role in application areas such as ecommerce where protocol participants require mutual guarantees that a transaction involving exchange of items has taken place in a specific manner. A protocol is fair if no protocol participant can gain any advantage over an honest participant by misbehaving. In addition, such a protocol is fault tolerant if the protoc...

In this paper we present an attack on a fair exchange protocol proposed by Wu and Varadharajan. We show that, after two executions of the protocol, a dishonest participant can collect enough information in order to obtain some secret information of the other participant. This precisely allows him to compute the final signature of the other participant in all subsequent executions of the protoco...

This paper presents a novel protocol for achieving secure and fair document exchange among multiparties. The protocol has the following characteristics: it employs no trusted (third) party when a majority of the parties involved behave honestly; it adopts a technique for integrity and originality verification of messages without use of either asymmetric (public key) or symmetric (conventional) ...

CONTEXT Previous studies have drawn attention to the importance of the trainee/trainer relationship in determining job satisfaction and motivation to learn. OBJECTIVES To study the relationship between pre-registration house officers and their consultants through exploring an interpersonal exchange and the emotional context in which the exchange took place. To consider any association between...

In recent years, the Internet is a major media to convey digital contents. Users can purchase or exchange the digital contents via the Internet. Due to the security problems of the Internet, mutual authentication between users must be ensured before exchanging digital contents. In addition, how to exchange the digital contents fairly via the Internet is another major problem since users may not...