Payments for Outsourced Computations

With the recent advent of cloud computing, the concept of outsourcing computations, initiated by volunteer computing efforts, is being revamped. While the two paradigms differ in several dimensions, they also share challenges, stemming from the lack of trust between outsourcers and workers. In this work, we propose a unifying trust framework, where correct participation is financially rewarded: neither participant is trusted, yet outsourced computations are efficiently verified and validly remunerated. We propose three solutions for this problem, relying on an offline bank to generate and redeem payments; the bank is oblivious to interactions between outsourcers and workers. We propose several attacks that can be launched against our framework and study the effectiveness of our solutions. We implemented our most secure solution and our experiments show that it is efficient: the bank can perform hundreds of payment transactions per second and the overheads imposed on outsourcers and workers are negligible.