A fair exchange protocol allows two parties to exchange items in a fair way, such that either both parties obtain the other's item or neither party does. In this paper, we propose a time sequence protocol for exch...A fair exchange protocol allows two parties to exchange items in a fair way, such that either both parties obtain the other's item or neither party does. In this paper, we propose a time sequence protocol for exchanging participants' warrants without a trusted third party(TTP). Then, each participant is able to sign a proxy signature on behalf of its opponent. Owing to the proxy signature's restriction, the scheme achieves the desired effect of fair exchange of digital signatures. Our scheme is based on a time sequence rather than computation, and can be realized without the use of a TTP, thus differing from the existing fair exchange schemes. Compared with a concurrent signature, the proposed scheme does not need to release a keystone to wake the signatures when they exchange information fairly. The only advantage to the initial party is that it has the right to determine whether the exchanged warrants are valid before a designated time. However, because of the properties of proxy signatures, the initial party ultimately derives no benefit from this advantage. After the designated time, there is no additional advantage to benefit the initial party.展开更多
基金supported by Funding of Jiangsu Innovation Program for Graduate Education(CXZZ12_0161)the Fundamental Research Funds for the Central Universitiesfunded by the Priority Academic Program Development of Jiangsu Higher Education Institutions ‘‘Internet of Things and Control Technology’’
文摘A fair exchange protocol allows two parties to exchange items in a fair way, such that either both parties obtain the other's item or neither party does. In this paper, we propose a time sequence protocol for exchanging participants' warrants without a trusted third party(TTP). Then, each participant is able to sign a proxy signature on behalf of its opponent. Owing to the proxy signature's restriction, the scheme achieves the desired effect of fair exchange of digital signatures. Our scheme is based on a time sequence rather than computation, and can be realized without the use of a TTP, thus differing from the existing fair exchange schemes. Compared with a concurrent signature, the proposed scheme does not need to release a keystone to wake the signatures when they exchange information fairly. The only advantage to the initial party is that it has the right to determine whether the exchanged warrants are valid before a designated time. However, because of the properties of proxy signatures, the initial party ultimately derives no benefit from this advantage. After the designated time, there is no additional advantage to benefit the initial party.
