O. Ussatova, S. Makilenov, A. Mukaddas, S. Amanzholova, Y. Begimbayeva, and N. Ussatov, “Enhancing healthcare data security: a two-step authentication scheme with cloud technology and blockchain”, EEJET, vol. 6, no. 2 (126), pp. 6–16, Dec. 2023.