PSFQ: A Blockchain-based Privacy-preserving and Verifiable Student Feedback Questionnaire Platform

Recently, more and more higher education institutions have been using student feedback questionnaires (SFQ) to evaluate teaching. However, existing SFQ systems have two shortcomings. The first is that the respondent of an SFQ is not anonymous. The second is that the statistical report of SFQs can be manipulated. To tackle these two shortcomings, we develop a novel SFQ system, namely PSFQ. In PSFQ, the respondent of an SFQ is mixed with multiple users by a ring signature. PSFQ uses an advanced ring signature approach to minimize the size of a ring signature when anonymity satisfies the requirements. Thus, the first shortcoming has been overcome. Moreover, all answers are encrypted by homomorphic encryption and stored on the blockchain, enabling users to verify the correctness of the statistical reports. Our demonstration will showcase how PSFQ provides confidential SFQ responses while ensuring the correctness of statistical reports.