Issuing electronic vouchers

摘要

A method of issuing electronic vouchers (V i ) which a user (U) may submit to a merchant (M) in exchange for goods or services comprises the steps of:
€¢ an issuer (I) receiving an electronic declaration (D i-1 ) from the user (U),
€¢ the issuer verifying the electronic declaration (D i-1 ), and
€¢ the issuer issuing a new electronic voucher (V i ) for use with the merchant (M) only if the electronic declaration comprises a signature (S M ) of a merchant on a previous electronic voucher (V i-1 *).
The vouchers (V i ) and declarations (D i-1 ) are preferably blinded by the user such that the user remains anonymous. However, the electronic vouchers (V i ) may contain the identity (Q) of the user (U), which identity may be revealed when a voucher is submitted more than once.