## 6 Conclusions  
This paper proposes a secure-by-design framework for monitoring health and well-being data for both local and remote monitoring. This system ensures that data confidentiality, data integrity, and data availability are maintained. It also ensures that only registered users are allowed to integrate the IoMT system into the health network, which helps in monitoring the connecting devices to protect the server from any form of DoS or DDoS attacks. To ensure real-time communication between the IoMT client and the server, it is necessary to use a secure key, but not a big key like RSA 4096 bits or above, because such key generation with a processing power of @1.8 GHz takes around 8-9 s; when it is an RSA 8192-bit key, it takes around 3 min on average, and when there is such a huge key size along with SHA 256, creating a digital signature and signing takes over 1 s. So, to meet real-time  
Figure 14: Air quality of the room and movement monitoring. Figure 15: Lighting and noise monitoring. requirements, it is ideal to adopt the signing process using RSA 2048 for low computation power; however, due to the lightweight nature of the AES, any secure key sizes from a 128-bit key to an AES 256-bit key can be adopted for real-time communication. So, it is recommended to use RSA 2048, which is not too big for the signing process with SHA 256, to attain real-time communication in the process of avoiding a non-repudiation attack and to authenticate the sender. The level of security, system constraints, and performance of the system should be balanced, and no parameters should outweigh the others; otherwise, the system will not be usable. The developed system ensures that MAC spoofing does not compromise the data confidentiality and integrity by maintaining data encryption, signing the data, and authenticating using a unique ID to detect and identify the device. The proposed system does not allow data tampering during transit, repudiation attacks are not possible because of digital signature and signing using the sender's private key, information disclosure is not possible due to the high level of encryption and the adoption of dynamic key management policies, and DoS and DDoS attacks are averted by monitoring and allowing only authorised and authenticated devices into the monitoring system. The impact of such a system is that it is easy to deploy securely and easy to adopt, and the solution is scalable across the population for e-health monitoring locally or remotely from anywhere in the world as long as there is a network connection. The developed system needs to be tested for its acceptance and adoption among potential users in hospitals and care homes to study the impact of such solutions, which will be carried out in future work. The system also needs to incorporate other aspects of secure-by-design features like the automatic detection of intrusion and threats, security controls, application failure recovery, patch management, etc. Other limitations of the proposed system are the lack of control over the access rights and limits over the data based on who is accessing them because the granularity of the data required by a doctor will be different from the nurse and so on. This aspect will be explored in the future. In terms of the hardware cost for the IoMT system development, it costs approximately GBP 120, mainly for using Raspberry Pi 4 with an HD camera and multiple sensors. The best thing about this prototype is that more sensors can be incorporated depending on the need with little or no modification to the system. [PERSON]. ([PERSON]), i.e., the corresponding author, and [PERSON] ([PERSON]) designed and developed the framework and conducted the implementation, testing, and validation of the secure IoMT system. [PERSON]. ([PERSON]), [PERSON] ([PERSON]), [PERSON] ([PERSON]), and [PERSON] ([PERSON]) supported the work by conducting a critical literature study, supporting drafting the paper, and drawing the diagrams and figures. C.D.-B. ([PERSON]) and [PERSON] ([PERSON]) supported [PERSON]. ([PERSON]) and S.K.