Alharbi, Eman, and Daniyal Alghazzawi. “Two Factor Authentication Framework Using OTP-SMS Based on Blockchain”. Transactions on Engineering and Computing Sciences 7, no. 3 (July 1, 2019): 17–27. Accessed April 19, 2024. https://journals.scholarpublishing.org/index.php/TMLAI/article/view/6524.