For the average homeowner considering a smart home, security remains top of mind. Visions of criminals hacking smart locks or gleaning personal information from internet-connected devices creates tremendous unease. However, the fear of these “micro-hacks,” though valid, are often overblown while the more damaging potential for “macro-hacks” are overlooked.
More destructive than a hacker on the local level gaining access to one home and its connected door lock or HVAC system, for example, is a hacker in the cloud with access to thousands of air conditioners. This type of macro-hack has the capability to cause a surge and bring down the grid within a widespread area affecting hundreds (or thousands) of homes. For example, in Dallas, TX, hackers recently activated emergency sirens late at night, frightening residents and disrupting homes for miles. This type of macro-attack is the concern of larger businesses and companies, but should also concern the average homeowner as well (even without a smart home since a grid fail or hacked siren system affects everyone nearby). If it concerns the average homeowner, it should certainly worry the developers and manufacturers producing the products for their smart homes.
Some devices (not all) on a secured internet network, even when deploying the highest levels of security, can be left vulnerable to exploitable holes or weaknesses. Differences in product categories (a connected door lock vs. a connected light switch) can translate into developers and manufacturers who think about security through the lens of the device category. A connected door lock manufacturer may implement the strictest level of security because if someone virtually opens a customer’s door, their reputation is on the line. In contrast, a company that manufactures a connected light switch may not feel that a hacked light turning on and off is as large of a problem as a picked lock. However, what may not be fully appreciated is that the security flaw within the light switch can be used to hack multiple devices installed across the network and beyond. It is through these unsecure pathways within the ecosystem that hackers get themselves “in” to execute micro and macro attacks. For this reason, developers, companies, and manufacturers must start thinking beyond just the security of their individual devices and focus on the security of the entire network ecosystem.
Historically, focus on security has tended to be on the local level rather than the entire network supporting the device. Additionally (within smart home protocols), previous security frameworks may have provided high-levels of security and encryption, but the choice to implement such measures was left up to manufacturers, most of which aren’t security experts or have dedicated staff to review and implement industry standard security measures. This results in an ecosystem of connected products with varying levels of security deployed throughout. As the threat of macro-hacking rises, the need to secure the ecosystem is more important than ever.
Cybersecurity advancements within the industry are being made to elevate security levels. However, in order to ensure this security, awareness of the problem and availability of easy-to-apply emerging security solutions must increase within the developer and manufacturer community.
Work to increase security on smart home devices is being done today. Let’s review the basics for what is needed to make this security possible. There are three layers of connected networks that matter for security: the wide area network (WAN), i.e. the Internet; the local area network (LAN) or “home network”; and the wireless personal area network (WPAN), consisting of the end-node devices. A number of problems can occur when trying to build secure solutions within these communication pathways. Among them are security attack threats, cryptographic computation power, available network bandwidth, code space, firewall policies, and efficient battery operation. All of these threats must be considered when developing a security framework for smart home. Z-Wave has addressed these concerns in a new security framework, Z-Wave Security 2 (S2).
To reinforce how high the level of security in Z-Wave has always been, it should be noted that it’s always used AES-128 levels of encryption. The U.S. government considers AES-128 safe enough for classified information up to the SECRET level. Combined with S2 authentication and nonce scrambling, there is no known method for overriding this protection—even using the power of a supercomputer. However, prior to S2, implementation of security was left to the device manufacturer to deploy. Of course, not all manufacturers have the same level of expertise, ability, or understanding of the need for high security, which left consumers open to micro and macro-level attacks.
S2 prevents hacker attacks by including encryption in the protocol itself. Instead of saying: “Send command to this destination,” it says: “Send secure command to this destination,” this ensures all transmissions are encrypted. Hackers cannot infiltrate or bypass security at this layer. Building security directly into the protocol also makes it easier for developers and manufacturers to develop security-enabled products. In the Z-Wave case, S2 secures the WPAN devices, DTLS secures the LAN, and TLS secures the WAN. Z-Wave’s Z/IP gateway supports all of these. The gateway implementation ultimately secures the LAN and WAN, whereas the Z-Wave device protocol supports S2.
To create this caliber of security, help from some unlikely partners- the hacker community, was needed. Through sharing the developing framework code in its entirety with hackers, the thoughts, additions, input and expertise of the hacker community was integrated into the new framework to preempt common hacking methods. Security architecture experts contributed to implement higher levels of security without negatively impacting other device features, like battery life.
The S2 security enabled framework is currently available for developers and its use has been made mandatory on all new devices submitted for Z-Wave certification. New S2 enabled devices are backwards compatible with existing non secure devices, and both can coexist in a network.
Ultimately, a smart home is only as secure as its weakest link. It’s no longer “good enough” for companies to only worry about the security of their own devices. In a world built on connectivity, understanding how all the devices that sit on the network interact and communicate securely with one another is more important than ever. Developers and manufacturers must be aware of the rising threat of macro-hacks and the solutions available to thwart them. To not do so is an affront to their customers (and their unsuspecting neighbors).