How lightweight encryption can protect critical infrastructure for smart cities

You might not think of your municipality as a smart city, but every day more urban areas fit the description. Smart cities depend on digitized processes, internet-of-things data streams and a variety of interconnected networks. They count on this data-powered foundation to manage city functions, share information among agencies and with the public and deliver crucial services to citizens.

In particular, today’s cities rely on data generation, capture and transfer to manage critical infrastructure. That includes electricity and natural gas distribution, water distribution and wastewater management, traffic lights and traffic monitoring, law enforcement and public safety, hospital operations and public health management as well as and health and human services delivery. In other words, there’s a lot riding on city networks.

But how safe is the data on those networks? As city IT managers are acutely aware, their digital infrastructures are increasingly under threat of cyberattack. Ransomware has hit cities harder than other government sectors. City governments are increasingly concerned that malicious cyber activity could spill over to them from the Ukraine War.

The good news is that there’s an effective way to protect critical municipal infrastructure, and that’s with small form factor, or lightweight, data encryption. Powered by the Trusted Data Format (TDF) open standard, lightweight encryption can be layered into the systems and applications agencies already use today, enabling a city to safeguard critical-infrastructure data throughout its lifecycle — without disrupting existing workflows. 

Encryption doesn’t have to change the way cities work; it simply gives them greater control of the data that’s already moving in and out of their technology ecosystem — enabling the relay of information quickly with greater security and confidence.

Small-scale encryption for far-flung devices

Data encryption applies mathematical algorithms to scramble data so that it can be read only by someone who holds the unique key to decrypt it. It offers a highly effective way of protecting data while it’s at rest on a device or in a database and while it’s in motion, traversing a network.

The only potential downside is that encryption can make file sizes larger. That presents two issues for smart cities. One is that small sensors at the edge of the network have limited compute power. The other is that most remote wireless network technologies employed by municipalities have very limited bandwidth.

The answer to those problems is lightweight encryption, which encrypts data packets without adding significantly to their size. Effective lightweight encryption provides all the data-protecting power of regular encryption, only tailored to the smaller data packets that flow across critical infrastructure networks.

The best way for cities to achieve lightweight encryption is through an open, government-approved standard. Agencies deploying thousands of edge devices to manage critical infrastructure don’t want to be locked into proprietary technology that has to be replaced if a vendor withdraws support.

That’s where TDF comes into play. TDF is an open standard for protecting sensitive data, approved by the Office of the Director of National Intelligence and widely used by the U.S. intelligence community. The technology applies military-grade, 256-bit encryption to wrap data objects in a layer of security and privacy.

Agencies can combine that encryption with attribute-based access control. ABAC authorizes access to data by evaluating the requester’s attributes, or characteristics. It’s a next-generation authorization model because it’s more finely tuned than the traditional role-based access control. ABAC can consider a combination of attributes and can be adjusted dynamically to comply with changing regulations.

Combining encryption with ABAC protects data throughout its lifecycle. Agencies retain control over how the data is accessed no matter where it’s shared, for as long as the data exists.

Micro encryption, macro advantages

Why is TDF especially well suited to smart cities? Because it’s available in a lightweight, binary variant that minimizes the encryption and ABAC to a payload that’s only 42 bytes. That’s well within the typical communications network limit of 250 bytes. Encrypted data packets traverse the network with virtually zero added latency.

Lightweight encryption is appropriate for any smart city use case where data needs protection from the edge to the core. Deploying lightweight encryption means agencies need no longer worry about the security capabilities built into edge devices, even if they were built with legacy libraries that have known vulnerabilities. With encryption and ABAC applied at the data-object level, it doesn’t matter whether hackers break into the device or the network -- because they still can’t read the data.

As more municipalities embrace smart city technologies, securing critical infrastructure data will only grow in importance. Effective lightweight encryption can ensure that the data agencies collect on remote sensors is never tampered with, from the moment it’s generated, until it’s stored on servers or shared with stakeholders – for as long as the data exists.

Shannon Vaughn is general manager with Virtru Federal.