Tipping Pennies? Privately Practical Anonymous Micropayments

We design and analyze the first practical anonymous payment mechanisms for network services. We start by reporting on our experience with the implementation of a routing micropayment solution for Tor. We then propose micropayment protocols of increasingly complex requirements for networked services, such as P2P or cloud-hosted services. The solutions are efficient, with bandwidth and latency overheads of under 4% and 0.9 ms, respectively, in the ORPay implementation, provide full anonymity (for both payers and payees), and support thousands of transactions per second.