JAN, Saeed Ullah; 						QAYUM, Fawad; 						KHAN, Ajab.
 SIP Issues and Challenges – A Scalable Three Factor Authentication Scheme.
<strong>Mehran University Research Journal of Engineering and Technology</strong>, [S.l.], v. 39, n. 2, p. 287-309, apr. 2020.
ISSN 2413-7219.
Available at: &lt;<a href="https://publications.muet.edu.pk/index.php/muetrj/article/view/1588" target="_new">https://publications.muet.edu.pk/index.php/muetrj/article/view/1588</a>&gt;. Date accessed: 26 apr. 2024.
doi: <a href="http://dx.doi.org/10.22581/muet1982.2002.07">http://dx.doi.org/10.22581/muet1982.2002.07</a>.