Many view smart cities as the future of urban living, promising to boost the efficiency and effectiveness of city services and the quality of life for residents while helping cities keep pace with growth and the associated pressure on aging infrastructures. To do this, smart cities must weave the Internet of Things (IoT) and interconnected devices into the existing technology infrastructure to bring entire communities online. However, this new wave of energy and excitement also brings new cyber risks that could impact the very existence of smart cities.

Smart cities are fast approaching mainstream, and for good reason: a 2018 United Nations study found that over 55 percent of the world’s population lives in an urban environment, and the top 33 cities all have populations in excess of ten million people. Across these vast urban landscapes, interconnected networks of IoT devices can do much to relieve congestion, reduce environmental impact, improve community health and safety, modernize city services and much more.

As connected devices proliferate, vulnerabilities in one area can extend into numerous other areas. In extreme cases, the consequences of a successful cyberattack could lead to disruption of crucial city services and infrastructure across health care, transportation, law enforcement, power and utilities, and residential services. Such disruptions could potentially lead to loss of life and breakdown of social and economic systems.

Cyber threats multiply

With the proliferation of IoT devices in smart cities, attackers now have countless entry points available to compromise a city’s systems. Making matter worse, many cities have chosen to deploy IoT sensors on top of existing systems. One example is sensors on established gas and water systems that are in turn connected to broader networks for data aggregation and analysis. Unfortunately, these sensors often have minimal security capabilities, and minimal ability to be upgraded over time as vulnerabilities are uncovered.

Another challenge is the lack of generally accepted standards governing the functioning of IoT-enabled devices. Even within the same city, various agencies and departments can select IoT devices from different vendors that use different communications protocols, different security models and generate data in different format. The outcome is that cities face a trade-off between interoperability and security. Fundamentally, every new device added to an IoT ecosystem adds a new attack surface or opportunity for malicious attack.

Integrated components

In addition to multiple layers of devices and sensors at the edge, a smart city also requires a network layer and a central core through which all data, communications and updates can be processed. To ensure success and maintain security across the network, it’s vital that all integrated components within the city’s IoT meet certain baseline requirements. These should include the following:

Scalable -- Devices should be paired with other devices for increased functionality and security and should remain open and available for system-wide updates. Scalability also means that older IoT devices can be easily switched out over time with more efficient components.

Compliant -- Systems and devices should be compliant with universal standards such as FIPS-2 or AEAD. Even though standards are no panacea, selecting compliant products can improve interoperability and reduce reliance on a single vendor.

Interoperable -- Devices must be built to communicate and function with one another, across departments.

Crypto-agile -- All communications within the IoT must be able to be encrypted, decrypted, and authenticated quickly to prevent availability issues and respond to threats quickly.

On-premises and cloud -- On-premise hardware security modules (HSM)allow for data storage in tamper-resistant modules at a secure location, while storing data in the cloud allows for ease of access to information across industries. A hardware security module is a physical computing device that safeguards and manages digital keys for strong authentication and provides crypto processing. Using both simultaneously or for different needs provides ease of access and secure backups.

In addition to the above considerations, one of the most important steps toward smart city security is a city-wide public key infrastructure (PKI). Multiple systems within the smart city cannot function securely without a PKI, including communication between devices and the authentication of messages in the IoT. Use of a universal standard for PKI compliance provide security and peace of mind for the entire smart city infrastructure.

As the smart city relies on a system of encrypted communications and sensitive data collection through IoT devices, the model should be secured via a PKI foundation of trust. Like the IoT, the use of PKI is vital in all sectors of the smart city, including transportation, environment, and business. PKI can be applied to a wide range of security solutions within the city infrastructure such as access control, device ID and lifecycle management.

Phased deployment

As cities begin to implement a smart infrastructure, they must enforce security requirements across every IoT device in the smart city ecosystem as well as the entire network. To prevent city-wide threats and disruptions, cities should have a comprehensive cybersecurity plan. Such a plan is complex and won’t happen overnight. Instead, most cities will employ a phased approach:

Phase 1, Initialization – As we see happening now, various city stakeholders are creating smart devices and systems that operate independently of one another, each with their own security solutions and standards. The risk is considerable without a central security and PKI model in place, but since the IoT network is often limited, the risk is somewhat moderated.

Phase 2, Connected -- As smart IoT applications expand, new programs will be put into place to connect and secure both new and existing systems. A universal model will be defined for secure communication and older, less secure deployments will be updated or replaced.

Phase 3, Integrated – In this final phase, the IoT infrastructure is established city-wide to connect the smart city ecosystem together. With a universal cryptographic security plan in place, the city can begin to fully realize the benefits of smart city technologies while maintaining strong defenses against cyberattack.

As urban centers continue to expand, the rise of the smart city draws nearer as a way to ensure quality of life and increase efficiencies. However, smart devices and systems pose new and potentially catastrophic threats to cities. By taking a long-term view, city planners and other stakeholders together with security solutions providers can pave the way for efficient and secure adoption of smart city systems and devices now and in the future.