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.