The Internet of Things (IoT) is revolutionizing how we interact with our homes, workplaces, and even cities. From smart thermostats to wearable fitness trackers, it’s estimated there are more than 18 billion of these devices. They connect our physical world to the digital sphere, creating a seamless ecosystem of convenience.
At the same time, this connectivity also opens doors to security vulnerabilities that many users are unaware of. One of the lesser-discussed threats in the IoT ecosystem is the side-channel attack — an insidious approach that leverages the physical side effects of these devices to extract sensitive information. Let’s get into the nitty-gritty and find out how to tackle it.
What are side-channel attacks?
A side-channel attack is not a direct attempt to breach a device via its code or software vulnerabilities. Instead, it exploits the indirect physical signatures that devices emit during their operations.
These signatures can include power consumption, electromagnetic radiation, timing data, or even acoustic emanations. For instance, an attacker could analyze the power consumption pattern of a device to understand when a particular operation is happening — such as the encryption of sensitive data — and use that information to infer critical details.
Imagine a hacker not sending a phishing email but instead monitoring system activity in an organization and finding the right time to attack. Scary, isn’t it?
The fact that IoT devices often lack the computing power for sophisticated encryption makes them particularly vulnerable to side-channel attacks. While side-channel threats have existed for decades in the context of high-level computing systems, the proliferation of interconnected, minimally-secured devices has created a new playground for attackers.
The vulnerabilities in IoT devices
There’s no denying that the ability to communicate with other devices is nothing short of revolutionary. Nevertheless, IoT devices have several inherent weaknesses that make them prime targets for side-channel attacks:
- Minimal processing power: Most IoT devices are designed to be cost-effective and energy-efficient, which means they lack the hardware resources to support advanced security protocols. This makes them more susceptible to attacks that analyze indirect signals.
- Default configurations and weak encryption: Many IoT devices are shipped with default passwords and minimal encryption. These shortcuts provide ample opportunities for attackers to listen in and analyze the device’s physical data leaks without even needing direct access to the device itself.
- Interconnected ecosystems: IoT devices typically operate within a connected network — if one device is compromised, it could potentially compromise the entire ecosystem. A side-channel attack on a single, relatively insignificant device — like a smart lightbulb — could open doors to far more critical systems, such as your home security cameras or smart door locks.
- Physical proximity: Many side-channel attacks require physical proximity, but in the case of IoT, proximity isn’t a major limitation. Think of a smart home in an apartment building; anyone within the vicinity might have an opportunity to collect data on what your smart devices are doing.
Real-world examples of side-channel attacks
Side-channel attacks on IoT devices have moved from theoretical scenarios to real-world threats. Even though the resources and knowledge required for such endeavors are exponentially greater than your average hack, several documented cases caused the cybersec community to pay attention.
In 2018, Researchers in Belgium (KU Leuven) successfully carried out a real-world side-channel attack on Tesla Model S key fobs, which are a type of embedded IoT device. The attackers used a combination of RF capture and computational techniques to extract the cryptographic key used by the key fob. This allowed them to clone the fob and steal the vehicle. While this started as a research project, similar attacks have since been documented by criminals exploiting these vulnerabilities to steal vehicles.
In 2016, several reports emerged in the United States about baby monitors being compromised. While much of the focus was on weak authentication, it was also found that some attackers utilized side-channel vulnerabilities related to Wi-Fi signal strength and timing patterns to infer when the monitors were actively transmitting. Attackers used these clues to determine when to attempt brute-force attacks or exploit unprotected access points, effectively timing their efforts to avoid detection.
If devices as crucial as baby monitors and cars are so easily compromised, that means nowhere is safe. People could be spending time with their families, immersing themselves in cherished memories, and a single faulty connection or outdated firmware could welcome all sorts of trouble. Now, just think about the level of risk governments and businesses are exposed to.
How side-channel attacks are executed
Side-channel attacks generally fall into two categories: passive and active.
- Passive attacks: In passive side-channel attacks, attackers observe the side effects of device operations without disturbing them. For example, they may monitor electromagnetic radiation or power consumption to deduce the internal state of the device.
- Active attacks: In active attacks, an attacker actively interacts with a device to force it to reveal more information. This might involve carefully timed interactions to observe how the device handles certain workloads, thereby allowing the attacker to infer sensitive data based on its responses.
These attacks rely heavily on understanding the physical operation of the device. Attackers gather data over time, analyzing the variations in signals to deduce patterns that reveal encryption keys, passwords, or other sensitive data.
Preventing side-channel attacks
Preventing side-channel attacks is challenging, especially in the context of low-cost IoT devices with limited computational resources. However, several strategies can mitigate the risks, mainly:
- Signal masking: Randomizing power consumption patterns or adding noise to electromagnetic emissions can make it significantly harder for an attacker to extract useful information. However, these solutions come with trade-offs in performance and efficiency — which may not be feasible for resource-limited IoT devices or those in key healthcare and industrial production.
- Shielding and hardware countermeasures: Special hardware shielding can reduce electromagnetic leaks, while modifications in device circuitry can make power analysis more challenging for attackers. These approaches are effective but often costly.
- Effective monitoring: Just as hackers monitor IoT devices to extract as much telemetric data as possible. Various tools like Amazon CloudWatch monitor key metrics like device states, logs and sensor readings and allow for instant adjustments.
- Software patching and encryption: While encryption alone is not a perfect defense against side-channel attacks, strong cryptographic protocols can make it harder for an attacker to glean useful information from side-channel data. Regular software updates and ensuring default passwords are changed can also help reduce exposure.
- User awareness: Many IoT users are unaware of the extent of their devices’ vulnerabilities. Manufacturers must take responsibility for educating users about safe usage practices, including securing devices with strong, unique passwords and minimizing unnecessary connections.
The future of IoT security and side-channel attacks
As IoT devices become more pervasive, the urgency to secure them against side-channel attacks will only grow. With billions of devices expected to be online in the coming years, the threat landscape is expanding rapidly. Manufacturers must strike a balance between affordability, convenience, and security—a challenging task given the constraints of typical IoT hardware.
However, more threats loom on the horizon. We’re nearing the cusp of quantum computing being applicable in more practical tasks, highlighting the need for adequate cryptographic protocols before it’s too late. At the same time, AI-aided cyber attacks are a growing concern, given the fact they allow even measly hackers to pack a punch.
Fortunately, we are seeing more and more IoT devices specifically designed to be resilient against side-channel attacks, employing advanced encryption techniques and hardware obfuscation. Likewise, AI doesn’t only have to serve a malicious purpose—it can also detect unusual patterns in power consumption or electromagnetic radiation, allowing devices to identify and shut down under attempted attacks.
The responsibility, however, doesn’t just fall on manufacturers. Organizations that deploy IoT devices at scale must also consider these risks and invest in the necessary countermeasures. Proper network segmentation, the use of intrusion detection systems, and physical security all must be taken care of before we continue dreaming of futuristic, interconnected smart cities.
Are we really ready for an interconnected lifestyle?
Side-channel attacks represent a clear and present danger in the evolving world of IoT. They are sophisticated, stealthy, and difficult to prevent outright — largely because they leverage the very physical properties of the devices themselves.
With IoT adoption showing no sign of stopping, awareness and proactive security measures become critical. Mitigating these hidden threats requires a multifaceted approach involving both hardware innovation and user education.
It requires manufacturers, developers, cybersecurity experts, and organizations to work together to mitigate and prevent these threats. But are we truly ready for such a vision of the world? Only time will tell if it’s possible.
