MAKHLOUF, Sassia, et al. “A New Directed Signature Scheme on a General Linear Group over a Group Ring”. Journal of Innovative Applied Mathematics and Computational Sciences, vol. 3, no. 1, May 2023, pp. 15-27, https://jiamcs.centre-univ-mila.dz/index.php/jiamcs/article/view/v3i1_129.