This article is part of the Communication and Systems Design Series: Fortifying Cyber Resilience in the IoT
What you'll learn:
- What is the biggest challenge in terms of security for IoT system designers?
- What does cyber reliability entail?
Embedded systems have always had some level of integrated security. At the most basic level, OEMs have wanted to protect their code base and other intellectual property (IP) from being copied and stolen by competitors trying to knock off their designs. Applications such as military systems also have incorporated means of preventing systems from being physically hacked.
Connecting devices to each other to create the Internet of Things, however, has forced embedded OEMs to reconsider what they mean by security. Over the past decade, we’ve seen numerous high-profile network hacks using simple equipment such as closed-circuit TV (CCTV) cameras and wireless printers.
The emergence of the smart home is only increasing the attack surface. Hackers have taken over smart doorbells and cameras to send creepy messages to small children supposedly safe at home. Someone even hacked a casino’s network through a fish-tank sensor.
Today’s smart embedded and connected systems must include ways to secure communications between devices, including mechanisms such as authentication and encryption. Updates, once performed manually by a trusted technician, now take place over the internet and must be secured to prevent hackers from “updating” systems with rogue code. Connected devices also need to secure sensitive data to protect individual privacy and safety.
To build such systems, OEMs have access to increasingly secure silicon, including MCUs like the Infineon PSoC 6 based on the Arm Cortex-M4 and -M0+. It integrates security technologies ranging from a secure execution environment and hardware-based cryptographic accelerators to secure boot and secure storage. With a secure foundation based in silicon, OEMs can design with security top-of-mind.
Unfortunately, relying on integrated security technology isn’t enough. Hardware-based security like root of trust and secure boot are only part of what makes a system secure. Consider the effectiveness of a reinforced steel door to protect your home if you forget to lock the deadbolt or leave a window open.
Cyber Resilience
This is perhaps the greatest challenge for embedded designers: Security has to be considered in terms of the whole system. The weakest link in the chain of security is where hackers will break into the network. At the same time, security must be implemented device by device.
Furthermore, OEMs don’t control the design of every device on the network. Market pressures require them to coexist with products developed by other companies who might not treat security as seriously. Thus, designers always must consider that a “fish sensor” might be connected to the same network trying to compromise all of the other devices.
Consequently, developers can’t think about security solely at a device level. Nor can they assume that other devices on the network are secure and trustworthy. If they do, the devices they trust can be used to hack them as well.
In many ways, the embedded industry is addressing these issues through new standards, protocols, and guidelines. However, there’s no need to reinvent the security wheel, so to speak. Enterprise networks have been pushing the boundaries of security for decades. The IoT, in many respects, is quickly becoming as complex as these networks. And if we want to make the IoT secure, we need to start treating it just like a real network.
For example, trust isn’t earned in a network. It’s authenticated and verified. An IT manager assumes hackers are always trying to break in. They also assume that every device joining the network might be masquerading as a legitimate device and just waiting for the right moment to bring the network down.
Moreover, IT has learned not to make the mistake to ever believe that their network is unhackable. They accept that hacking is inevitable and have instead put measures in place to minimize the impact of an attack when it occurs that balances security, risk, cost, and complexity.
This is Cyber Resilience. If we want the IoT to succeed, we need to learn from traditional networks how to build cyber resilience into our devices just as seriously as we do security.
That’s the purpose of this column—to explore security and cyber resilience. In the coming months, we’ll consider the different ways hackers can attack an IoT network and ways to protect against them. We’ll look at the different layers and levels of an embedded IoT system, from what’s happening under the hood of the MCU to security issues in production manufacturing to operating securely in the cloud. And that’s just scratching the surface.
There’s a lot to cover, so let’s get started.
Read more from the Communication and Systems Design Series: Fortifying Cyber Resilience in the IoT