With the operationalisation of lockdowns and restrictions on public gatherings, education systems across the entire globe were confronted with an urgent need to reconsider alternative forms of teaching, learning and assessment. Some institutions in developing countries were especially hard-hit by the shift owing to inadequacies in training and infrastructure because unlike their more developed counterparts who had already made inroads into adopting online technologies, some institutions in the developing world had no such technologies in place. As such, the shift to online learning was rushed and somewhat a "learning on the job" experience for students and educators. While remote online teaching, learning and assessment are novel experiences for many higher education institutions, developing countries are incessantly presented with many challenges, particularly when safeguarding academic integrity. Invigilated assessments, which are often considered more secure, are not an option given the current situation, thus detecting any cheating would be significantly challenging. As a result, this study examined assessment security in the digital domain and critically evaluated the practices to safeguard academic integrity in developing countries across three Southern African universities, including associated challenges. Underpinned by the pragmatist paradigm, the study employed a mixed-methods research approach that utilised in-depth qualitative and quantitative data from university managers, lecturers and students to investigate how academic integrity is safeguarded in the advent of online learning. Our findings revealed that although the transition to online learning and assessment was abrupt, higher education institutions have generated creative strategies to secure and ensure the continuity of learning and assessment. Such strategies include administering several versions of the same examination, as well as the use of "text-matching" software to detect the originality of work done by students. Based on the findings of the study, it was recommended that to guarantee the authenticity of online assessment, institutions must ensure that assessment practices relate to real-world needs and the context in which students can apply acquired knowledge.