A design for cloud-assisted Fair-Play Management System of online contests with provable security

• We present a Fair-Play Management System that guarantees provable security of online contests over a cloud.
• We build a security model for fair-play and privacy in online contest.
• We achieve synchronized start for multiple contests with heterogeneous users in cloud by Randomness-reused Identity-Based Encryption.
• We show provable security of the system based on the security model.

Contest hosting faces more fairness challenges and security risks from real to virtual. Malicious competitors are easier to perform false starts without preventing unfairness. Eavesdroppers have higher possibility to obtain any contest file without the intended right. The leakage of competitors’ identities is with higher probability. However online contest is popular for the convenience. It performs with diverse forms such as auctions, games and exams.With incremental requirements on fair-play, we build a new security model and propose the generally designed framework of Fair-Play Management System (FPMS) over clouds. Involving “cloud” as public storage will release much burden of real-time transmissions in networks, though it may double the security risks from outside. Moreover it is harder to guarantee to all competitors the synchronical start of a contest under inside attacks such as false starts. Facing challenges on confidentiality, anonymity and fairness simultaneously, we find that public-key encryption is more effective than symmetric-key encryption to support multiple data owners in a cloud. By leveraging a Randomness-reused Identity-Based Encryption (RIBE) scheme, FPMS can resist all mentioned attacks within a cloud-assisted environment, and support security towards multiple data owners that respectively host multiple contests. As a complement, the analysis on the provable security of FPMS is given finally, as well as a further analysis on the fair-play performance. Though transmission delay is hardly avoided under provable security requirements, the FPMP performs quasi synchronical with ignorable delay differences to deliver the start order.