IoT devices employ encryption to ensure data integrity and confidentiality. Encryption is the process of converting data into a secure format that can only be read with the correct decryption key. Authentication, Firewall, and Latency are important in IoT, but they do not directly ensure data integrity and confidentiality as encryption does.

In the 1980s, machines communicating their status to a computer is a clear example of Machine-to-Machine (M2M) communication. This concept laid the foundation for the development of the Internet of Things (IoT) where devices and machines can communicate with each other autonomously.

Digital certificates in IoT devices primarily aid in device authentication. These certificates ensure that the device is genuine and authorized to access or exchange data within the network. While data storage and encryption are important, they are not the primary role of digital certificates in IoT.

With the influx of IoT devices, "Biometric Authentication" has become a prevalent technique to safeguard users' identities. Biometric methods, like fingerprint or facial recognition, offer strong user authentication.

For bi-directional communication in IoT, the protocol often recommended due to its low overhead and real-time capabilities is WebSockets. WebSockets provide full-duplex communication channels over a single TCP connection. They are well-suited for scenarios where low latency and real-time data exchange are crucial, making them a popular choice in IoT applications.

The low latency feature of 5G is critical for remote surgery. Low latency ensures minimal delay in data transmission, which is crucial in surgical procedures where real-time responses are essential. High bandwidth, wide coverage, and energy efficiency are also valuable but have different priorities in this scenario.

To ensure that machinery operates within safe temperature ranges, a manufacturing company should implement real-time monitoring and control systems. These systems use sensors to continuously measure the temperature of machinery and can automatically adjust operations or send alerts in case of temperature deviations, ensuring safety and efficiency.

M2H (Machine-to-Human) communication involves machines or devices communicating with humans. Your smartphone notifying you of low battery is a clear example of this. It's a machine (smartphone) alerting a human (you) about an important status change, which is a common use case in IoT.

AWS IoT Core is a platform that allows securely connecting and managing IoT devices. It provides a suite of services for IoT, including device registration, communication, and data processing in the cloud. Cloud computing services, developing mobile applications, and managing databases are related but not the primary purpose of AWS IoT Core.

Compromised bootloaders can be detected using digital signatures. Digital signatures verify the authenticity and integrity of the bootloader code, ensuring it hasn't been tampered with before executing it during the boot process.

MQTT (Message Queuing Telemetry Transport) is a widely used framework for connecting and managing IoT devices. It provides a lightweight, efficient communication protocol for IoT. CoAP, IoTivity, and AllJoyn are also IoT protocols and frameworks.

FreeRTOS is a real-time operating system (RTOS) that is commonly used in IoT devices. RTOS is essential for managing tasks with strict timing requirements in IoT applications. Windows 10, Ubuntu, and MacOS are general-purpose operating systems not designed for real-time tasks.