TY  - GEN
N2  - Fair exchange protocols let two mutually distrusted parties exchange digital data in a way that neither can cheat. At CCS 2017, Campanelli et al. proposed two blockchain-based protocols for the fair exchange of digital coins and a certain service, i.e., ?proofs of retrievability? (PoR), that take place between a buyer and seller. In this work, we identify two serious issues of these schemes; namely, (1) a malicious client can waste the seller?s resources, and (2) real-time leakage of information to non-participants in the exchange. To rectify the issues, we propose a ?recurring contingent PoR payment? (RC-PoR-P). It lets the fair exchange reoccur while ensuring that the seller?s resources are not wasted, and the parties? privacy is preserved. We implemented the RC- PoR-P. Our cost analysis indicates that the RC-PoR-P is efficient. The RC-PoR-P is the first of its kind that offers all the above features.
ID  - discovery10153741
PB  - Cryptology ePrint Archive
UR  - https://eprint.iacr.org/2021/1145
A1  - Abadi, Aydin
A1  - Murdoch, steven
A1  - Zacharias, Thomas
T3  - Paper 2021/1145
KW  - Cryptographic protocol
KW  -  blockchain
KW  -  smart contracts
KW  -  fair exchange
TI  - Recurring Contingent Payment for Proofs of Retrievability
AV  - public
Y1  - 2021/09/10/
EP  - 50
N1  - This work is licensed under an Attribution 4.0 International License (CC BY 4.0).
ER  -