  The rapid evolutions in micro-computing, mini-hardware manufacturing, and
machine to machine (M2M) communications have enabled novel Internet of Things
(IoT) solutions to reshape many networking applications. Healthcare systems are
among these applications that have been revolutionized with IoT, introducing an
IoT branch known as the Internet of Medical Things (IoMT) systems. IoMT systems
allow remote monitoring of patients with chronic diseases. Thus, it can provide
timely patients' diagnostic that can save their life in case of emergencies.
However, security in these critical systems is a major challenge facing their
wide utilization. In this paper, we present state-of-the-art techniques to
secure IoMT systems' data during collection, transmission, and storage. We
comprehensively overview IoMT systems' potential attacks, including physical
and network attacks. Our findings reveal that most security techniques do not
consider various types of attacks. Hence, we propose a security framework that
combines several security techniques. The framework covers IoMT security
requirements and can mitigate most of its known attacks.
