Efficient fair conditional payments for outsourcing computations

The outsourcing computations in distributed environments

suffer from the trust problems between the outsourcer and

the workers. All existing solutions only assume the rational lazybut-

honest workers. In this paper, we first introduce the rational

lazy-and-partially-dishonest workers in the outsourcing computation

model. In addition, we propose a new fair conditional payment

scheme for outsourcing computation that is only based on traditional

electronic cash systems. The proposed construction uses a

semitrusted third party T to achieve the fairness and efficiency.

However, is only involved in the protocol in the exceptional case,

namely in the case of disputes. Moreover, since neither the secret

sharing/splitting scheme nor the cut-and-choose protocol is used

for the generation or verification of the payment token, our solution

clearly outperforms the existing schemes in terms of efficiency.