A Multi-denomination Electronic Invoice Protocol

Invoices are the voucher to reimburse for official expenses. However, fake paper invoices spread in our lives. The appearance of electronic invoices can solve the problem of fake invoices. Before the business purchases invoices from Inland Revenue, The Inland Revenue and the business identify the authenticities of each other and generate a temporary session key between them through Key Distribution Center as intermediary. After a consumer pays for official expenses, the business generates a detailed consumption inventory which must be signed by the consumer and inserted into the invoices. The final invoices signed by the Inland Revenue, the business and the consumer will be time stamped in a form of a three-line cross timestamp by Timestamp Authority. After the detailed consumption inventory can be decrypted by the consumer´s public key, the unit will reimburse for the consumer´s expenses. This electronic invoice protocol is characterized with security and efficiency.