Evaluation of Probabilistic Payment Systems

With the development of pay-per-view and multimedia streaming services, there is an increasing demand for practical micropayment mechanisms. In this paper, we investigate the applicability of probabilistic payment schemes for micropayments and propose a framework to evaluate them. The framework consists of a well structured parameter vector of characteristics such as transaction cost, delay, computation overhead, overcharging and anonymity. It is applied to lottery tickets, coin flipping and MR2 schemes. Results show that lottery tickets and MR2 have nearly the same transaction computation overhead, delay, anonymity, loss risk and non-refutability. MR2 scheme has lower traffic cost, it provides message integrity, authentication, no overcharging, while lottery tickets scheme prevents double spending. MR2 scheme is best suited for micropayments but it still needs a lot of work in respect of building a working micropayment system