Construction of Graduation Certificate Issuing System Based on Digital Signature Technique. Journal of Engineering, [S. l.], v. 21, n. 06, p. 15–36, 2015. DOI: 10.31026/j.eng.2015.06.02. Disponível em: https://joe.uobaghdad.edu.iq/index.php/main/article/view/411. Acesso em: 25 mar. 2025.