DeExam: A Decentralized Exam Administration Model using Public Blockchain

In exams, which are intended to evaluate capability, it is practically difficult to detect errors or mistakes made by test providers and scorers, as the correct/incorrect decision logic is often not disclosed. Therefore, we propose a sustainable exam administration model with enhanced reliability and transparency, utilizing a public blockchain, without a centralized authority. The blockchain records the hash values of the correct answers, decision condition, and decision result, which cannot be tampered with afterward. We implemented our proposed method using Bitcoin Core and used it to conduct a CTF (Capture The Flag) competition with over 100 participants. No fatal flaws were observed, thereby confirming the viability of the method.