1. O’Gorman, L.: Comparing passwords, tokens, and biometrics for user authentication. Proc. IEEE 91(12), 2021–2040 (2003)
2. Chen, Y.-L., Ku, W.-C., Yeh, Y.-C., Liao, D.-M.: A simple text- based shoulder surfing resistant graphical password scheme. In: 2013 IEEE International Symposium on Next- Generation Electronics (ISNE), pp. 161–164. IEEE (2013)
3. Yan, Q., Han, J., Li, Y., Deng, H., et al.: On limitations of designing usable leakage-resilient password systems: attacks, principles and usability (2012)
4. Shah Zaman, N., Tariq Jamil, K., Syed Rahul, H., Mohd Zalishman, J.: A text based authentication scheme for improving security of textual passwords. Int. J. Adv. Comput. Sci. Appl. 8(7), 513–521 (2017)
5. Alsulaiman, F.A., El Saddik, A.: Three-dimensional password for more secure authentication. IEEE Trans. Instrum. Meas. 57(9), 1929–1938 (2008)