Examinations are high-stakes assessments, and their credibility depends on keeping questions confidential, verifying the identity of candidates, and protecting the integrity of examination results. This review compares three recent studies that address examination security from different perspectives. The first study uses a questionnaire survey and literature review to examine encryption and authentication practices in Jordanian universities. The second presents a blockchain and smart contract prototype designed to improve the security of online examinations. The third investigates an optical examination paper designed to reduce the possibility of lateral viewing during paperbased tests. These studies were selected by the author; therefore, this review represents a comparative analysis of a small set of studies rather than a systematic literature review. Each study was examined based on its security focus, methodology, evidence, reported findings, and limitations. The numerical results reported in the experimental study were also recalculated using the published values. Looking at the results as a whole, the findings indicate that the practices reported in the survey rely heavily on passwordbased authentication and the use of unencrypted question banks. The blockchain-based approach provides tamperevident storage of examination results, but it does not provide quantitative evaluation or address candidate impersonation. The optical examination paper reports statistically significant effects, although the study uses relatively small samples and contains some inconsistencies in its reported numerical results. The review identifies several important research gaps, including the lack of clear threat models, limited evaluation of cost and processing time, potential privacy concerns related to blockchain records, limited consideration of cheating assisted by generative artificial intelligence, and the absence of a common benchmark for comparing security solutions. Based on these findings, five possible research directions are suggested, along with a conceptual layered framework for improving examination security.

Dishant Nitin Chaudhari, Hitesh Nilesh Mahajan, Sharvari Sandeep Gosavi, Drushna Shantanu Sarode, Prof.Kiran Borade, "Comparative Review of Encryption, Authentication, Blockchain and Optical Approaches to Examination Security" International Journal of Computer Science and Engineering Development, V1(4): Page(106-114) September - October 2026. ISSN: 3139-0862. www.ijcsed.com. Published by Scientific and Academic Research Publishing.