Effient Electronic Cash Using Batch Signatures.

All known anonymous electronic cash protocols are inefficient compared to other electronic payment protocols. This is because much of the complexity of the protocols is devoted to ensuring the anonymity of the consumer. This problem is addressed with an extension of Brands' electronic cash payment protocol using batch cryptography. Batch signature generation is used to improve the efficiency of the withdrawal process so that multiple coins can be withdrawn for almost the cost of only one Brands' coin withdrawal. As a consequence coins withdrawn together can be linked. Batch verification is also used to increase the efficiency of payment. We show that the security of the original scheme is maintained and the level of privacy provided by the cash scheme can be determined by the customer. [ABSTRACT FROM AUTHOR]