In the last few years, advanced software for processing medical images has gained a great interest in modern medicine. In fact, it provides valuable clinical information, and hence, can significantly improve diagnosis and treatment. Nevertheless, implementing these imaging tools often requires an important capital budget in both IT applications and hardware. This solution can unfortunately cause a dramatic increase in operational expenses and medical costs. To mitigate this problem, medical providers are shifting their interest onto using cloud computing, particularly the Software-as-a-Service (SaaS) model, instead of in-house data centres. In this case, healthcare professionals rely on remote applications delivered by an external provider to process patients' digital records. Interestingly, in this paradigm, consumers are billed based on software utilization. Besides, cloud computing promises to offer a better Quality of Service (QoS), including availability, elasticity, trust, response time, security assurance, etc. Regardless of its significant financial benefits, the transition to the cloud environment gives rise to security and privacy problems, especially in the healthcare domain. Recently, various security measures