BSSSQS: A Blockchain-Based Smart and Secured Scheme for Question Sharing in the Smart Education System

Abstract

In this study, we present a new scheme for smart education utilizing the concept of a blockchain for question sharing. A two-phase encryption technique for encrypting question papers (QSPs) is proposed. In the first phase, QSPs are encrypted using a timestamp, and in the second phase, previously encrypted QSPs are encrypted again using a timestamp, salt hash, and hash from the previous QSPs. These encrypted QSPs are stored in a blockchain along with a smart contract that helps the user to unlock the selected QSP. An algorithm is also proposed for selecting a QSP for the exam that randomly picks a QSP. Moreover, a timestamp-based lock is imposed on the scheme so that no one can decrypt the QSP before the allowed time. Security analysis is conducted to demonstrate the feasibility of the proposed scheme against different attacks. Finally, the effectiveness of the proposed scheme is demonstrated through implementation, and the superiority of the proposed scheme over existing schemes is proven through a comparative study based on different features.