SHA-2 and SHA-3 based sequence randomization algorithm

Providing questions with unique sequence helps to encourage participants integrity in an examination. In this study, Secure Hash Algorithm (SHA) 2 and 3 have been proposed and evaluated in a question shuffling problem for computer based test. Two strategies were tested to use the hash algorithms. The first utilized a few of the most significant digits of the hash value and the second treated all digits of the hash value as equally important. Entropy analysis and running time analysis were performed to assess the proposed method in terms of randomness and computational efficiency. SHA-2 implemented with the first strategy is superior with entropy of 3.88792 bits and real execution time of 1.76585 seconds. The evaluation result demonstrates no significant difference between the randomness of the sequences generated by SHA-2 and SHA-3. In terms of computational efficiency, SHA-2 demonstrated faster execution time than SHA-3.