Mobile Payment Protocol for Micropayments: Withdrawal and Payment Anonymous

This paper presents an efficient and practical protocol to carry out micropayments, based on the use of anonymous mobile cash, that provides anonymity and unlinkability to customers. The mobile cash used in the protocol can be of different value and denomination. It is official after a bank signs it with a specific private key. The bank stores the relation between the mobile cash´s value and its corresponding public key. The scheme prevents double spending and forgery attacks. A mobile device that supports Java applications and Bluetooth technology is required. Through the use of pseudonym certificates customers can be authenticated using WTLS protocol without disclosing personal information. The protocol requires a low computational cost.