# Firewall Best Practices for Securing Smart Healthcare Environment: A Review
## 1 Introduction  
The integration of Internet of Things (IoT) with smart healthcare devices brought many opportunities and challenges. Healthcare professionals and medical practitioners can monitor their patients remotely and deliver critical medical care using these devices. The digitization and rapid increase of smart healthcare environments offer a wide range of benefits that not only help healthcare professionals and healthcare providers, but also offer better, and around the clock service to patients. Moreover, patients can be monitored remotely, and healthcare professionals can share their experiences in real-time through these interconnected environments. In addition to traditional \"information systems\" implemented in healthcare networks, the growth of the IoT paradigm allows various mobile devices and sensors to be part of a healthcare network for monitoring these systems and patients in real-time, but also make these networks more vulnerable and increase the probability of cyberattacks [1]. Such attacks usually target sensitive healthcare records that not only affect the safety and privacy of patients, but also threaten the integrity of the data. Each day, thousands of healthcare systems are threatened worldwide, and \"invisible\" attackers cause irreversible damages. For example, in 2017, the average cost of a single cyberattack in the UK was $8.7 million, while it was $11.5 million in 2018 [2], registering an increase of 31%. Therefore, it is equally important to have proper management and continued monitoring for all healthcare entities. Cybersecurity is an economic, military, and social issue, and securing healthcare systems can essentially be resumed by the respect of three properties: integrity, confidentiality, and availability [3, 4]. Firewalls play a critical role in securing and accessing electronic health records and network-enabled medical devices across and beyond the network where these services are accessible through the cloud [5]. In fact, firewalls have always been the first line of defense for healthcare system security. To ensure those properties, a good firewall must always act as a filter between the traffic coming from internal networks (outgoing traffic) and the traffic generated from outside and generally less secure networks (ingoing traffic) than protecting networks from external attacks and risks, with consequent enforcement of security, and no restricted policy to allowed users. The effectiveness of a firewall system depends on several environmental conditions and constraints, such as the placement of a firewall and the nature of data that need to be protected. Moreover, users should always be able to access resources behind the firewall without facing any issues [6; 7]. Smart healthcare architectures are like any other network systems, in general, yet considering the data contained in these systems, the architecture is largely different from other similar types of architecture. More specifically, considering the life-critical data of a patient, financial implications and data governance compliance requirements require additional layers of security for smart healthcare architectures, and this makes these architectures different from other similar network systems. The landscape of cybersecurity threats and new security vulnerabilities to smart healthcare systems is constantly growing. The effective and efficient use of firewalls reduces the impact of cyber threats on smart healthcare environments. More specially, cloud-based firewalls play an important role while safeguarding cyber-attacks against smart healthcare devices carrying sensitive data and information. Therefore, it is important to have proper firewall placement for a smart healthcare environment to protect against attacks and threats. Despite providing the various advantages and benefits in securing healthcare systems, firewalls are still vulnerable to attacks. In this paper, we investigate the most known firewall types and their compatibility to smart healthcare environments.