A SECURE ONLINE EXAMINATION SYSTEM USING SMART CONTRACTS

Covid19 pandemic has affected many sectors including education. All types of schools (public and private) have started to provide online education systems to their students to prevent spreading the disease. The online education system has brought many advantages besides stopping the spread of the disease. The students have more time since the lectures are not in class, it reduces the cost for the students since they physically do not go to school, and it provides flexibility in the lectures that students decide their schedule to attend the classes. However, there are some challenges in the online education system. The system needs to be available for the students when they take exams, view their exam results, and upload their exams for assessment. Since the lectures and exams are taken online, the data is very crucial. The data contains sensitive information such as exams, answers, scores, name, date of birth, address, phone number, government identification number, etc. A traditional online education system has a centralized infrastructure governed and managed by a single entity. This results in the system having single-point-of-failure attacks. This paper proposes an online examination system based on a smart contract and a blockchain. The blockchain eliminates single-point-of-failure attacks. The teachers write questions and store them in the blockchain. Only authorized students retrieve the exams from the blockchain by using smart contracts. The students submit their completed exams at predefined times. Then, the teachers evaluate the students’ exams and put the results into the blockchain. Their exam scores are protected from any unauthorized entities by encryption. Students can freely see and view their scores at any time. Then, the students can show their results to any other third parties (once they apply for an internship or job) that they have completed the courses successfully. The system also uses a decentralized storage (off-chain) system to eliminate scalability problems. Off-chain storage (InterPlanetary File System) stores students’ exams, answers, and exam results while the corresponding content identifiers of the files are stored in the blockchain. The proposed system is resilient to malicious teachers who can manipulate the exam results. In addition, the proposed system also provides a method for dishonest students who can complain about their exam results. In other words, the proposed system solves any conflicts between entities.