The Internet of Things (IoT) and Operational Technology (OT) have revolutionized industries by connecting billions of devices and enabling automation, data-driven insights, and improved efficiency. However, this increased connectivity also introduces significant security challenges.
Protecting IoT and OT environments requires a robust security framework, and a critical component of this framework is Public Key Infrastructure (PKI) and certificate management. PKI provides the foundation for secure communication, authentication, and data integrity in these complex ecosystems. However, traditional PKI solutions—designed for slow growing enterprise environments—often struggle to scale for industrial IoT (IIoT) and OT ecosystems. Legacy PKI were typically built with a monolithic architecture, meaning that it was a single, unified, self-contained unit. This architecture poses several challenges when it comes to modern PKI, especially with respect to PKI for IoT and OT. Monolithic architecture makes it challenging to scale and continually upgrade the platform. This is especially limiting in the context of IoT and IoT where organizations need to manage a large volume of devices. Modern PKI, especially PKI for IoT and OT, is built on microservices architecture, which is highly scalable, flexible, responsive, and reliable. These modern PKI solutions are much better suited to managing the identities of significant volume of IoT and OT devices and systems.
The recent introduction of IoT security standards and regulations has helped establish best practices, but implementing PKI for IoT at scale remains a challenge. Responding to this need, cryptographic leaders have launched dedicated IoT solutions for PKI and certificate management that provide the automation and scalability required to secure IoT devices throughout their lifecycle.
What is OT (Operational Technology) Security?
Operational Technology (OT) refers to systems that monitor, control, and automate industrial processes in sectors like energy, manufacturing, and transportation. Unlike IT, which manages digital assets, OT ensures the continuous operation of critical infrastructure. As OT networks become more interconnected through Industrial IoT (IIoT) and cloud-based monitoring, cyber risks have increased, making security essential.
OT systems control power grids, water treatment plants, and manufacturing lines. SCADA systems manage electricity distribution, while PLCs and DCS automate industrial processes. In transportation, OT governs railway signaling and air traffic control. Cyberattacks on these environments can cause power outages, production halts, supply chain disruptions, and safety hazards, as seen in incidents like the Colonial Pipeline ransomware attack and the Stuxnet malware.
Unlike IT security, which prioritizes data protection, OT security focuses on availability and safety. Public Key Infrastructure (PKI) and Certificate Lifecycle Management (CLM) are essential for securing OT environments, ensuring strong authentication, encrypted communications, and automated certificate renewal. Organizations must also implement network segmentation, secure remote access, and comply with standards like IEC 62443 and NIST 800-82.
As IT and OT continue to converge, enterprises must adopt proactive security strategies to prevent cyber threats, ensuring operational resilience and regulatory compliance.
What is the difference between IoT and IIoT?
The Internet of Things (IoT) is a concept that encompasses a broad range of devices, including consumer-facing devices and complex industrial equipment. The Industrial Internet of Things (IIoT) is a subset of IoT that specifically focuses on industrial devices and systems that are often subject to specific compliance regulations. Here is a breakdown:
| Security Factor | IoT (Internet of Things) | IIoT (Industrial Internet of Things) |
|---|---|---|
| Primary Focus | Connectivity & convenience – Designed to enhance automation, monitoring, and user experience. | Reliability, safety, & security – Ensures operational continuity, protects critical infrastructure, and prevents system failures. |
| Lifespan of Devices | Varies greatly (2-10+ years) – Consumer IoT devices typically have shorter lifecycles due to technological advancements and frequent upgrades. | Long (10-20+ years) – IIoT devices often control mission-critical systems that must remain operational for decades with minimal upgrades. |
| Security Updates & Patch Management | Updates often available, but adoption varies – Many IoT devices support firmware updates, but consumers and enterprises often delay or ignore security patches. | Updates challenging due to operational constraints – IIoT devices may run on legacy systems where updates require planned maintenance to prevent downtime. |
| Network Environment | Typically cloud-connected and internet-facing – IoT devices rely heavily on cloud services for data processing, analytics, and remote access. | Mix of cloud, on-premises, and edge computing – IIoT systems often use air-gapped or segmented networks to isolate critical operations from external threats. |
| Authentication & Access Control | Basic authentication – Many IoT devices rely on username/password authentication, which is prone to breaches. | Strong authentication required – IIoT mandates mutual TLS (mTLS), PKI-based authentication, and role-based access control (RBAC) to ensure secure communication. |
| Data Sensitivity & Privacy Concerns | High risk of personal data exposure – IoT collects user behavior, location data, health records, and other personally identifiable information (PII). | Operational data critical to business continuity – IIoT devices generate real-time machine data, production metrics, and infrastructure control signals, which must be protected from tampering. |
| Encryption & Data Protection | Varied implementation – Some IoT devices lack encryption, while others use TLS for data transmission. | Strict encryption standards – IIoT environments require end-to-end encryption (TLS, AES-256, and PKI-based identity management) to prevent unauthorized access. |
| Regulatory & Compliance Requirements | Varied by industry – Consumer IoT compliance varies based on regional laws (GDPR, CCPA, NIST 8259), but enforcement is often lax. | Highly regulated – IIoT must comply with strict industry standards (IEC 62443, NIST 800-82, NIS2, PCI DSS, ISO 27001, and CISA guidelines). |
| Impact of Cyberattacks | Data loss, privacy breaches, consumer disruption – IoT breaches can expose sensitive user data or disrupt connected services. | Physical damage, operational downtime, financial loss, safety risks – IIoT attacks can disrupt manufacturing plants, energy grids, and industrial control systems (ICS), leading to physical harm or financial losses |
| Common Threats | Device spoofing, ransomware, unsecured APIs, weak credentials, DDoS attacks (e.g., Mirai botnet). | Supply chain attacks, insider threats, SCADA/PLC exploitation, targeted ransomware (e.g., Triton, Stuxnet, Colonial Pipeline attack). |
Understanding IoT and OT Security Considerations
IoT and OT security demands a device-centric approach. This is because these ecosystems often comprise millions of devices with diverse lifecycles, varying levels of security posture, and in some cases limited processing capabilities. Strong device identity, secure communication, and automated certificate management are essential to mitigate the risks of unauthorized access, data breaches, and operational disruptions.
The challenge with managing IoT and OT devices and systems is adopting an identity-based security approach. IoT and OT deployments are machine identities, that require management within a Public Key Infrastructure (PKI). PKI provides the framework for issuing and managing digital certificates, which serve as verifiable digital identities for devices. These certificates enable secure authentication, data encryption, and integrity checks, ensuring that only authorized devices can communicate and access sensitive information. Certificate lifecycle management (CLM) solutions simplify the management of these certificates throughout their lifecycle, from initial issuance and deployment to renewal and revocation, preventing outages, ensuring compliance, and mitigating security risks.
IIoT Security and Compliance
As Industrial IoT (IIoT) adoption grows, securing connected industrial systems has become a top priority. Unlike traditional IT environments, where centralized security controls are common, IIoT deployments consist of highly distributed, long-lifecycle devices that interact with critical infrastructure. This makes securing IIoT particularly complex, requiring a robust identity framework, strong authentication, and automated certificate lifecycle management (CLM) to ensure system integrity, compliance, and resilience against cyber threats.
There are a number of key regulations and standards that impact IIoT, that vary depending upon the nature of the devices and systems as well as the industry.
IEC 62443: A Framework for Industrial Cybersecurity
The IEC 62443 standard is the most comprehensive global cybersecurity standard for industrial automation and control systems (IACS). It applies to component manufacturers, machine builders, and plant operators, ensuring a trusted and secure relationship between IIoT devices and industrial systems. The framework outlines the need for:
- Device identification and access control using PKI-based authentication.
- System integrity through secure firmware updates and code signing to prevent unauthorized modifications.
- Confidentiality and encrypted communication, mandating TLS-based secure data transmission.
The IEC 62443 framework includes security levels from 0 to 4, with PKI becoming mandatory at Level 2, addressing attack scenarios based on hacker sophistication, resources, and motivation.
Although the IEC 62443 is a global standard that is not mandated, it forms the basis for critical cybersecurity frameworks:
United States and Canada:
- NIST 800-82 (Guide to Industrial Control System Security)
- CISA (Cybersecurity and Infrastructure Security Agency) Industrial Control Systems (ICS) Best Practices
- NERC CIP (North American Electric Reliability Corporation Critical Infrastructure Protection) standards for the energy sector
European Union:
- NIS2 Directive, which mandates stricter cybersecurity controls for critical infrastructure operators and IIoT deployments
- Cyber Resilience Act (CRA), requiring cybersecurity-by-design for industrial equipment and connected devices
EU IIoT Regulations: Cyber Resilience Act, NIS2, and Machinery Directive
The European Union’s evolving cybersecurity regulations focus on standardizing IIoT security across industries:
- Cyber Resilience Act (CRA): Establishes security-by-design requirements for connected devices, ensuring that all IIoT manufacturers integrate strong authentication, secure firmware updates, and encrypted communications.
- NIS2 Directive: Expands security mandates for critical infrastructure sectors, requiring device identity verification, real-time threat monitoring, and compliance reporting.
- Machinery Directive: Focuses on ensuring the cybersecurity of industrial machines, enforcing PKI-based authentication for IIoT endpoints.
Enterprises operating in Europe or supplying IIoT devices to European markets must now integrate PKI-driven identity security and certificate lifecycle automation to comply with these directives.
IEEE 802.1AR: Secure Device Identity Standard
The IEEE 802.1AR Secure Device Identity Standard establishes a framework for assigning cryptographically verifiable identities to devices, ensuring they can be uniquely authenticated and trusted within a network. This standard is particularly relevant for IoT, Industrial IoT (IIoT), Operational Technology (OT), and enterprise security deployments, where strong device identity management and certificate-based authentication are critical for securing communications and preventing unauthorized access.
IEEE 802.1AR-compliant device identities are referenced in multiple industrial security standards, including:
- OPC 10000-12, which defines built-in certificate management services for IIoT systems.
- OPC 10000-21, which outlines secure device onboarding requirements using PKI-based authentication.
By implementing IEEE 802.1AR-compliant identities, organizations can simplify device authentication and certificate management, reducing security risks such as device spoofing, unauthorized network access, and supply chain attacks.
RFC 8995 (BRSKI): Automating Secure Device Onboarding
The Bootstrapping Remote Secure Key Infrastructure (BRSKI) standard addresses secure device onboarding in IIoT environments, enabling devices to automatically enroll in a PKI-based identity management system. This ensures:
- Trusted, automated provisioning of digital certificates for IIoT devices.
- Seamless integration with industrial control networks, reducing manual onboarding complexity.
- Prevention of unauthorized devices accessing critical infrastructure through PKI-based verification.
RFC 8995 aligns with zero-trust security principles, ensuring that only authenticated and authorized IIoT devices can participate in industrial networks.
Securing IoT and IIoT Identities: PKI and CLM
As IoT and IIoT adoption continues to grow, it’s increasingly critical for organizations to establish a robust identity framework to ensure secure communication, authentication, and data integrity across all connected devices. Public Key Infrastructure (PKI) and Certificate Lifecycle Management (CLM) provide the foundation for device authentication, encrypted communications, and secure software updates. Without a well-managed PKI program, organizations face significant security risks, including unauthorized device access, data interception, and certificate outages.
PKI provides the foundational trust layer for securing IoT and IIoT identities. It does this by using trusted Certificate Authorities (CAs) to issue X.509 digital certificates to devices, linking each identity to a cryptographic key pair. These certificates enable strong authentication and encrypted communication. They act as verifiable digital passports, ensuring that only authorized devices can communicate within an industrial or enterprise network.
PKI secures IoT and IIoT environments by enabling:
- Mutual Authentication: Both devices authenticate each other using certificates before transmitting sensitive data.
- Encrypted Communication: Certificates enable TLS encryption, preventing man-in-the-middle (MitM) attacks and data interception.
- Secure Code Signing & OTA Updates: Ensures that only verified software and firmware updates are deployed, protecting against tampered or malicious updates.
However, simply implementing PKI is not enough—organizations must have centralized certificate lifecycle management (CLM) policies to prevent misconfigurations, expired certificates, and unauthorized certificate use.
Self-Signed Certificates for IoT? Major Security Risk
Many organizations attempt to self-manage certificates by issuing self-signed certificates rather than using a trusted Certificate Authority (CA). This approach creates significant security gaps:
- Lack of Identity Validation: Self-signed certificates do not provide a verifiable identity, making it easy for attackers to impersonate devices.
- Unmanaged Expiration & Renewals: Without a lifecycle management process, expired certificates can lead to authentication failures and operational downtime.
- No Centralized Oversight: Security teams lack visibility into which devices are using self-signed certificates, increasing the risk of compromised certificates being exploited.
To illustrate the issue, consider Transport Layer Security (TLS), the protocol used in many OT environments for secure communication. TLS relies on a two-step process:
- TLS Handshake: The TLS handshake verifies the authenticity and validity of the certificate presented by each device.
- TLS Record: Uses symmetric encryption to secure the communication session.
When a device presents a self-signed certificate, there is no external verification of its authenticity. Imagine an employee trying to enter a secure office building using a homemade badge they created themselves. Without proper verification from a trusted authority, there’s no way to know if they are who they claim to be. This lack of authentication poses a security risk, as unauthorized individuals could gain access to sensitive areas. The same logic applies to machine identities, like IoT / IIoT devices and systems.
Certificate Lifecycle Management (CLM) for IoT and IIoT
Managing digital certificates across diverse IoT and IIoT ecosystems requires a structured and automated Certificate Lifecycle Management (CLM) solution. Manual certificate management is impractical given the scale and heterogeneity of these environments, where millions of devices may require authentication and secure communication. A centralized, policy-driven CLM approach ensures continuous security, compliance, and operational reliability for connected devices.
Key Components of CLM for IoT and IIoT
1. Issuing X.509 Certificates from a Trusted CA
Ensuring device authentication and trust begins with issuing X.509 certificates from a trusted Certificate Authority (CA) rather than relying on self-signed certificates. Each certificate binds a unique cryptographic identity to an IoT or IIoT device, allowing it to:
- Prove its identity to other devices, networks, or cloud services.
- Establish secure, encrypted communication channels using Transport Layer Security (TLS).
- Prevent device spoofing by ensuring that only legitimate, authorized devices can interact with the network.
An enterprise-grade CLM system enables organizations to:
- Issue certificates at scale, assigning cryptographic identities to devices during manufacturing or onboarding.
- Ensure interoperability with various CA infrastructures (public, private, or hybrid) to meet diverse deployment needs and regulatory requirements (IEC 62443, NIST 800-82, NIS2, etc.). The choice of CA infrastructure often depends on whether an organization needs to maintain control over its own CA (private) or leverage the services of a third-party CA (public). Hybrid approaches can also be used to balance control and scalability.
- Automate certificate provisioning for new IoT/IIoT deployments, reducing manual errors and improving efficiency.
2. Automating Certificate Renewals & Revocation
IoT and IIoT environments rely on continuous connectivity, and expired or revoked certificates can lead to authentication failures, operational disruptions, and security vulnerabilities. Without automated certificate lifecycle management, organizations risk:
- Device outages and service disruptions due to expired certificates.
- Security gaps where expired or revoked certificates are exploited by attackers.
- Operational delays and increased manual effort required for certificate renewals.
A CLM solution mitigates these risks by:
- Automating certificate renewal before expiration to avoid downtime and maintain continuous operation.
- Setting flexible expiration policies tailored to device risk levels, industry best practices, and compliance mandates.
- Enabling immediate revocation of compromised or unauthorized certificates, preventing rogue devices from accessing the network. Efficient revocation often requires the effective use of Certificate Revocation Lists (CRLs) and the Online Certificate Status Protocol (OCSP), especially in large-scale IoT and IIoT environments.
- Integrating with IoT/IIoT device management platforms to automate certificate provisioning and rotation.
3. Providing Centralized Visibility & Auditing
Managing certificates across distributed IoT and IIoT deployments requires real-time visibility and comprehensive reporting. Without centralized monitoring, security teams may be unaware of expired, duplicated, or unauthorized certificates, leading to compliance violations and security risks.
A robust CLM solution provides:
- A centralized dashboard for monitoring the status of all certificates (issued, expired, and revoked) across the entire IoT/IIoT ecosystem.
- Real-time alerts and automated policy enforcement to prevent devices with invalid certificates from operating on the network.
- Detailed audit trails and comprehensive compliance reporting aligned with industry standards and regulations, such as IEC 62443, NIST 800-82, and ISO 27001.
- Integration with Security Information and Event Management (SIEM) systems for proactive threat detection and security monitoring. Some organizations, especially those with large-scale IoT/IIoT deployments, may also utilize dedicated PKI monitoring and CLM analytics platforms alongside SIEM for enhanced scalability and operational visibility.
4. Enforcing Policy-Based Access Controls
IoT and IIoT deployments often involve a diverse set of devices, users, and third-party services, all requiring proper authentication and authorization. Without strict policy enforcement, attackers can exploit weak access controls to gain unauthorized entry into industrial networks or compromise sensitive data.
To address these challenges, a CLM solution must:
- Define and enforce granular certificate issuance and renewal policies, ensuring that only trusted entities can request and obtain certificates.
- Utilize role-based access control (RBAC) and multi-factor authentication (MFA) to restrict certificate management privileges and prevent unauthorized access.
- Support secure boot mechanisms and firmware signing to ensure that only trusted code and applications are executed on IIoT devices.
- Integrate with zero-trust security models, requiring continuous authentication and authorization for all IoT and IIoT devices attempting to access network resources.
- In high-assurance environments, such as critical infrastructure, access control for certificates is often further strengthened by leveraging Hardware Security Modules (HSMs) and policy-based cryptographic enforcement mechanisms to prevent unauthorized access and misuse of certificates.
CLM within your IoT PKI Framework
Implementing automated CLM is essential for organizations to:
- Maintain uninterrupted IoT and IIoT operations by preventing authentication failures and device outages caused by expired certificates.
- Reduce human errors and manual effort associated with certificate management, freeing up IT and security teams for more strategic tasks.
- Meet industry security standards and regulatory requirements by enforcing consistent certificate management policies and best practices.
- Proactively protect against cyberattacks targeting IoT and IIoT devices, such as device impersonation, expired certificate exploitation, and unauthorized network access.
By integrating PKI and automated CLM, organizations can establish a resilient, scalable security infrastructure that protects IoT and IIoT environments throughout the entire device lifecycle, from initial onboarding to decommissioning.
Selecting the Right IoT PKI and CLM Solution
As organizations scale their IoT and IIoT deployments, choosing the right Public Key Infrastructure (PKI) and Certificate Lifecycle Management (CLM) solution is critical to ensuring strong authentication, secure communication, and regulatory compliance. An effective IoT PKI and CLM platform must be highly scalable, automated, and seamlessly integrated with existing security architectures.
Key Criteria for Selecting an IoT PKI and CLM Solution
When evaluating IoT PKI and CLM solutions, consider these key criteria:
Scalability and Performance:
- The solution should be able to handle the scale of your IoT deployment, supporting millions or even billions of devices.
- Performance is crucial to ensure minimal latency and efficient operation, especially for time-sensitive applications.
- Consider whether the solution offers flexible deployment options, such as cloud-native, on-premises, or hybrid, to meet your specific operational needs.
Automated Certificate Lifecycle Management:
- Robust automation capabilities are essential for efficient certificate management throughout the entire lifecycle, including issuance, provisioning, renewal, and revocation.
- Look for solutions that integrate with your existing IoT device management platforms and security tools to streamline operations and reduce manual effort.
Strong Cryptographic Security:
- The solution should support strong, NIST-approved cryptographic algorithms, such as RSA, ECC, and post-quantum cryptography (PQC), to ensure long-term security and compliance.
- Consider augmenting with solutions that offer secure key storage options, such as Hardware Security Modules (HSMs) or Trusted Platform Modules (TPMs), to protect cryptographic keys from unauthorized access and compromise.
Zero-Trust & Compliance Readiness:
- Ensure the solution aligns with relevant industry standards and regulations, such as IEC 62443, NIST 800-82, ISO 27001, and NIS2, to support compliance efforts.
- Integration with zero-trust security frameworks is crucial for enforcing strong authentication, authorization, and least-privilege access for all IoT and IIoT devices.
Cloud, Edge, and On-Prem Deployment Flexibility:
- The solution should offer flexible deployment options to support your specific IoT architecture, whether it’s cloud-based, on-premises, edge-focused, or a hybrid approach.
- Consider solutions that provide offline authentication mechanisms for air-gapped or critical infrastructure environments with limited or no internet connectivity.
Centralized Visibility & Monitoring:
- Centralized management and monitoring capabilities are essential for maintaining an overview of all certificates and their status.
- Look for solutions that provide real-time certificate analytics, dashboards, and reporting to support compliance tracking, proactive threat detection, and efficient incident response.
- Integration with Security Information and Event Management (SIEM) solutions can further enhance security monitoring and incident response capabilities.
Purpose-Built IoT PKI Solutions
As IoT and IIoT ecosystems expand, traditional enterprise PKI solutions struggle to meet the unique scalability, automation, and security requirements of connected devices. To address these challenges, several leading cybersecurity and cryptography providers offer purpose-built PKI solutions for IoT and IIoT that support secure device identity, authentication, and lifecycle management.
Keyfactor Command for IoT
Keyfactor, a leading vendor for PKI and CLM solutions, provides a comprehensive IoT security platform: the Keyfactor Command for IoT.
Key Benefits of Keyfactor Command for IoT
- Enhanced Security: Protect against unauthorized access, data breaches, and malicious firmware updates.
- Simplified Compliance: Meet regulatory requirements and industry best practices for IoT security.
- Reduced Costs: Streamline operations and automate certificate management to lower operational costs and time-to-market.
- Improved Efficiency: Automate certificate lifecycle processes, freeing up resources for strategic initiatives.
Key Features of Keyfactor Command for IoT
Secure Device Provisioning:
- Issue and embed unique cryptographic identities for millions of devices.
- Provision certificates at any stage of the manufacturing process, from factory to field.
- Support on-device key generation (ODKG) for enhanced security.
Secure Firmware Updates:
- Ensure only authorized firmware updates are installed on devices.
- Secure the firmware signing and delivery process with policy-driven workflows and centralized tools.
- Protect signing keys with integrated HSMs.
Device Integrity and Secure Communication:
- Verify device identity and firmware integrity with secure boot and encryption mechanisms.
- Integrate with trusted platform modules (TPMs) and other hardware security technologies.
- Enable secure communication channels with encrypted TLS or IP VPN connections.
Automated Certificate Lifecycle Management:
- Capability to automate the complete certificate lifecycle, including issuance, provisioning, renewal, and revocation.
- Integrate with existing PKI or leverage managed PKI services.
Supply Chain Integration:
- Integrate with complex IoT supply chains and manufacturing processes.
- Support diverse trust models, chipsets, operating systems, and manufacturing systems.
- Securely provision devices even in untrusted manufacturing environments.
For organizations with a significant volume of IoT and IIoT systems and devices, Keyfactor Command for IoT establishes a robust and secure foundation for their IoT deployments, ensuring the confidentiality, integrity, and availability of their connected devices and data.
Selecting your IoT PKI and CLM
Choosing the right PKI solution for IIoT and OT begins with an in-depth understanding of your needs as well as the business, compliance and security outcomes you are aiming to realize from the solution. At Accutive Security, we often begin with a PKI Assessment that is tailored to your organizational needs from a cybersecurity, operational and compliance perspective. Once we have established a baseline and identified any gaps with PKI best practices, we leverage our extensive partner network and the Accutive Security Innovation Lab to conduct demos and proof of concepts with leading PKI vendors, including Keyfactor and Venafi.
This approach allows you to:
- Evaluate Leading Solutions: Gain hands-on experience with different PKI and CLM solutions to determine the best fit for your specific requirements.
- Validate Functionality: Test the capabilities of the solutions in your own environment to ensure they meet your performance and security needs.
- Identify Integration Points: Explore how the solutions integrate with your existing infrastructure and security tools.
- Develop a Comprehensive Strategy: Create a roadmap for implementing and managing your chosen PKI solution, including deployment, integration, and ongoing management.
Our team of experts can guide you through the entire process, from initial assessment and vendor selection to implementation, integration, and ongoing support. We can help you establish a robust and secure PKI foundation for your IoT and OT deployments, ensuring the confidentiality, integrity, and availability of your critical IoT, IIoT and OT assets.
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