Practical and efficient fair document exchange over networks

Fairness in Physical Products Delivery Protocol

“…The offline TTP-based fair exchange protocols (such as in [1]- [3], [11], [13], [17]) do not rely on the TTP during the exchange of items. Rather, the parties will exchange their items directly and the TTP will be contacted in the case of dispute between the participating parties.…”

“…In the literature consulted, the focus for the use of fair exchange protocols is in the context of digital products and their payments (as in [1], [2], [11], [13], [17]); the exchange of emails and receipts [12]; and the exchange of two digital signatures on a contract [3], [4]. The use of fair exchange protocols for physical products has, however, not received its due attention, even though most of the products sold online are physical in nature.…”

Provable Fair Document Exchange Protocol with Transaction Privacy for E-Commerce

“…Fair exchange protocols can be classified into different groups based on the type of content exchanged: (i) fair document exchange protocols [4][5][6][7][8][9][10]; (ii) optimistic fair exchange protocols of digital signature [11][12][13][14][15]; (iii) electronic contract signing protocols [16][17][18][19][20][21][22]; and (iv) certified e-mail/e-goods delivery protocols [23][24][25][26][27][28][29][30]. Optimistic fair exchange protocols of digital signature and contract signing protocols exchange digital signatures fairly.…”

“…Involving the online TTP in each transaction of the fair document exchange protocol remarkably decreases performance, especially in a multi-receiver context. Therefore, researchers have proposed several fair document exchange protocols with offline TTP [4,[6][7][8][9][10]. The main idea of these studies is that the sender first sends the ciphertext of his/her own document before obtaining the expect document from the opposite party.…”

“…In the first strategy [6][7][8][9][10], the offline TTP helps the sender encrypt the document, and then generates its certified commitment. However, the sender may attempt to fairly exchange the same document with many participants.…”