The implementation and testing of an existing efficient and secure micropayment scheme on the Android platform is described in this paper. The scheme was originally presented in another paper [1] by some of these authors.

In this paper, the authors review the scheme, which makes use of a partially blind signature and a hash chain. Coins containing the partially blind signatures move from the bank to the merchant. The coins have a specified shelf life. Protocols are shown for withdrawing, spending, and other actions. The system workflow, based on the protocols, is presented.

The main result of the paper is the testing of the scheme on both high-performance and low-performance Android cell phones. The time required to complete a transaction was measured at several seconds and the amount of storage space required was less than 350 bytes. Generally, the high-performance phone was about 25 percent faster than the low-performance unit. The times were short because the coins were short, reflecting the small sums being transferred. Longer coins, or larger amounts, did require appreciably more time, although this time could be reduced by a pre-computation procedure. The scheme does appear promising. The paper is straightforward, with some sample code.