PPETS-FGP: Privacy-Preserving Electronic Ticket Scheme with Fine-Grained Pricing

Electronic tickets (e-tickets) are electronic versions of paper tickets, which enable users to access intended services and improve services’ efficiency. Generally, to buy discounted tickets, users must convince ticket sellers that their attributes (i.e. age, profession, location) satisfy the ticket price policies. Hence, privacy issues have been the primary concerns of e-tickets users. In this paper, a privacy-preserving electronic ticket scheme with fine-grained pricing (PPETS-FGP) is proposed to protect users’ privacy and implement fine-grained pricing. The proposed PPETSFGP scheme captures the following features: (1) Users can buy different price tickets from ticket sellers without releasing their exact attributes; (2) Each user’s transaction records cannot be linked; (3) Tickets cannot be transferred and double spent; (4) The security of the proposed PPETS-FGP is formally proven and reduced to wellknown (q-strong Diffie-Hellman) complexity assumption. To the best of our knowledge, it is the first provable e-ticket system where both privacy-preserving and fine-grained pricing are addressed.