| Abstract: | Electronic check systems, as one of electronic payment systems, are more desirable than other electronic cash systems. In the system, only a single cheek is used to pay any price that is not more than the face value. The main problem in check systems is to design an efficient refund mechanism that makes refired cheeks undistinguished from initial checks during payment and deposit. The problem of anonymity control also called fairmess is also an important issue in check systelns. All check systems yet are unconditional anonymity that opens the door to misuse for crime such as laundering and blackmailing. In this paper, the notion of anonylnity revocation is introduced to electronic check system for the fitst thne, and a model of fair electronic check system is proposed. An effieient fair online electronic check system with reusable refund is presented. In the system, a passive trustee is elnployed to revoke the anonymity of unhonest users. Moreover, the system solves the reusability problem of refunds thanks to the RSA-based partially signature. The system is efficient and meets all basic security requirements. |
