IoT PKI

Internet of Things (IOT)

Driving Digital Transformation

The Internet of Things (IOT) has been one of the major technology drivers of Digital Transformation in the world over the last few years, across industry sectors. The number of connected devices already exceeds the number of human beings on the planet, and research indicates that we are likely to see around 50 billion connected devices over the next five years making up the smart, connected planet.

The applications of IOT range from smart homes, smart buildings, smart cities, connected vehicles, smart manufacturing, smart retail, medical devices in healthcare, fitness/wellness trackers, wearable devices, and more. With the rollout of related technologies such as 5G and Internet Protocol (IP) version 6, which are designed to support billions of connected devices, IOT as a technology is all set to play a pivotal role in our digital future.

Quick Answer: Why Does IoT Depend on PKI?

IoT depends on PKI because passwords don’t scale to billions of connected devices. Digital certificates let each device prove its identity, verify firmware before installing it through code signing, and encrypt machine-to-machine communication, without a human entering a credential. Ponemon Institute research found that around 41% of respondents already name IoT as the top technology trend driving PKI adoption.

Executive Summary

As IoT adoption scales toward tens of billions of connected devices, password-based identity management breaks down and certificate-based PKI becomes the practical option for device authentication, firmware code signing, and encrypted communication. This post covers why IoT security risk scales with device count, why PKI specifically solves the machine-to-machine authentication problem, a practical checklist for closing common IoT PKI gaps, and how IoT certificates fit into broader certificate lifecycle management.

Who Should Care About IoT PKI

Securing IoT deployments with PKI touches identity, security architecture, platform operations, and compliance. Here is what each role should do.

PKI Administrators

Issue and track device identity certificates and firmware code-signing certificates at IoT scale, and make sure certificate discovery extends to every connected device, not just enterprise servers and endpoints.

Security Architects

Design device onboarding and machine-to-machine authentication around certificate-based identity from day one, since retrofitting PKI onto tens of thousands of already-deployed devices is far harder than building it in.

Platform Teams

Integrate certificate issuance into device provisioning and firmware release pipelines so every device gets an identity certificate and every firmware update is code signed before it reaches the field.

Compliance Teams

Confirm that IoT devices collecting personally identifiable information, especially in healthcare and wellness, secure that data in transit using PKI-based encryption, and document any device category that doesn’t as accepted risk.

CISOs

Treat unmanaged IoT device identity as risk that scales with fleet size, and sponsor a certificate lifecycle program that covers device certificates and firmware signing certificates with the same rigor as enterprise TLS and code signing.

Why This Matters: Data and Deadlines

According to DigiCert’s Trust Pulse Survey (July 2, 2025), nearly half of enterprises experienced a certificate-related outage in the past year, and 18.5% of affected organizations reported losses exceeding $250,000, with 37.5% of those incidents tied specifically to expired certificates. At IoT scale, an expired device certificate doesn’t just cause a single outage, it can disconnect an entire fleet of devices from the network simultaneously.

The CA/Browser Forum’s Ballot SC-081v3, approved April 11, 2025, phases maximum public TLS certificate validity down to 200 days starting March 15, 2026, 100 days starting March 15, 2027, and 47 days starting March 15, 2029. While this schedule targets public TLS certificates, it signals the same direction IoT device certificates are heading: shorter validity periods that make manual renewal across thousands or millions of devices completely impractical, and automated certificate lifecycle management essential.

NIST finalized its post-quantum cryptography standards, FIPS 203 (ML-KEM), FIPS 204 (ML-DSA), and FIPS 205 (SLH-DSA), on August 13, 2024. IoT devices often stay in the field for a decade or more, far longer than typical enterprise IT hardware, so device identity and firmware signing certificates issued today need a crypto agility path to post-quantum algorithms before those devices retire.

Need for IOT security

As worldwide IOT adoption goes up, the risk of security breaches also goes up, since each of those billions of connected devices could be vulnerable to an attack. Also, considering the scale of IOT deployments, the economic impact of IOT security breaches will also be felt at a proportionately massive scale.

Likewise, one worrying trend is that vast numbers of connected devices do not have adequate security safeguards and are vulnerable to breaches. Some of the key security risks in IOT deployments include attackers using a connected device as an entry point into the network, introducing malware to alter the function of the device, controlling the device remotely, or tapping into data from the device.

Apart from the economic impact, the nature of IOT technology is such that physical security of individuals as well as organizations can be at risk. For example, altering the function of a device could have physical security implications: a CCTV camera that appears to be working fine, but is showing a “dummy image” instead of the real view, resulting in a threat of a physical intrusion into a home or company premises.

How and why PKI is becoming essential for IOT security?

We have seen in earlier articles how Public Key Infrastructure (PKI) is a set of roles, policies, hardware, software and procedures needed to create, manage, distribute, use, store and revoke digital certificates and manage public-key encryption. Recent research from Ponemon Institute indicates that over the last few years, IOT is becoming a major driver for PKI adoption. The percentage of respondents who believe that IOT is the most important technology trend driving PKI adoption has nearly doubled to around 41%. The research also predicts that more than 40% of IOT devices in use by 2021 will primarily rely on digital certificates for identification and authentication.

The primary reason why IOT security is becoming synonymous with PKI is scale. As mentioned earlier in this article, most predictions indicate more than 50 billion connected devices on the planet over the next few years. Even a single compromised device can have an enormous security impact, it is difficult to comprehend the scale of impact if many devices are compromised.

Connected devices interact with each other through machine to machine (M2M) communication. Each of these billions of interactions will require authentication of device credentials for the endpoints to prove the device’s digital identity. In such scenarios, an identity management approach based on passwords or passcodes is not practical, and PKI digital certificates are by far the best option for IOT credential management today.

IOT devices will also need regular patches and upgrades to their firmware, with code signing being critical to ensure the security of the downloaded firmware, another example of the close linkage between the IOT world and the PKI world.

Certificate management for connected devices, including revocation of expired certificates, is another example where PKI can help to secure IOT devices.

In some sectors such as healthcare and wellness, IOT devices might collect personally identifiable information (PII). With government regulations worldwide mandating secure transit (and storage) of PII data, PKI can help ensure compliance with the regulations by securing the communication channel between the IOT device and the gateway.

IoT PKI Glossary

Quick, extractable definitions for the terms used throughout this post.

Term	Definition
Public Key Infrastructure (PKI)	The roles, policies, hardware, software, and procedures used to create, manage, distribute, use, store, and revoke digital certificates and manage public-key encryption.
Machine-to-Machine (M2M) Communication	Direct data exchange between connected devices without human involvement, requiring device-to-device authentication.
Device Identity Certificate	A digital certificate issued to an individual connected device that lets it authenticate itself to a network or gateway.
Code Signing	Digitally signing firmware or software with a certificate so a device or OS can verify the publisher’s identity and confirm the code hasn’t been tampered with.
Certificate Revocation	The process of invalidating a certificate before its expiration, used to disable compromised or decommissioned IoT devices.
Personally Identifiable Information (PII)	Data that can identify a specific individual, often collected by healthcare and wellness IoT devices and subject to regulatory protection.
Certificate Lifecycle Management (CLM)	The process and tooling used to discover, issue, renew, and revoke certificates automatically across every PKI-enabled device and application.

IoT PKI Issue Checklist: Impact, Action, and Owner

Issue	Business Impact	Recommended Action	Owner
Devices authenticate with shared passwords or static keys	A single leaked credential can compromise an entire device fleet	Issue unique device identity certificates during provisioning	Security architects, platform teams
Firmware updates are not code signed	Malicious or tampered firmware can be installed without detection	Sign all firmware releases with a code signing certificate	Platform teams
No centralized tracking of device certificates at scale	Expired certificates can disconnect large numbers of devices at once	Bring device certificates into an automated CLM program	PKI administrators
Healthcare/wellness IoT devices transmit PII unencrypted	Regulatory non-compliance and exposure of sensitive personal data	Encrypt the device-to-gateway channel using PKI-based encryption	Compliance teams, security architects
Compromised devices cannot be revoked quickly	A breached device can remain active on the network indefinitely	Implement fast certificate revocation and monitoring for device fleets	PKI administrators, CISOs

Certificate Lifecycle Management and PKI Modernization

Device identity certificates and firmware code-signing certificates need the same discovery, issuance, and renewal discipline as any other part of a PKI modernization program, just at a much larger scale. CertSecure Manager automates certificate discovery, issuance, and renewal across IoT device fleets so no device certificate expires unnoticed.

Organizations scaling PKI across large IoT deployments without operating that infrastructure entirely in-house can rely on PKI-as-a-Service for a managed, cloud-hosted certificate authority capable of issuing at device scale. Building a machine identity inventory through CBOM Secure helps surface every certificate already in use across a device fleet, and completing a PQC readiness assessment ensures long-lived IoT devices have a migration path toward crypto agility and post-quantum algorithms. Encryption Consulting’s PQC Center of Excellence provides guidance on sequencing that migration.

For more on why certificate automation matters across the environment, see our Education Center articles on the stages in a certificate’s lifecycle and how to avoid certificate outages. For related enterprise application scenarios, see Enterprise applications and PKI – Part 1 and Part 2, and for a deeper look at IoT device protection see PKI – IoT’s Path to Security.

Key Takeaways

The proliferation of connected devices today, projections for billions of devices in the next few years and the continued growth in the number of applications across industry sectors is an indicator of the enormous promise of the Internet of Things (IOT). This promise however could be undermined by the lack of adequate security safeguards with IOT devices. PKI provides some of the best options for IOT security including device identity management, code signing for device firmware, and encrypted communication between devices and other endpoints such as IOT gateways.

Measuring Success and Ongoing Audits

Track the percentage of deployed devices with valid, automatically renewed identity certificates, the percentage of firmware releases that are code signed, and how quickly a compromised device’s certificate can be revoked. Audit certificate issuance logs and expiry dashboards across the device fleet on a recurring basis, quarterly for policy-driven factors like the CA/Browser Forum validity schedule, and continuously for certificate expiry, so a device fleet never silently falls back to an unprotected state.

Last updated: August 2026. Last verified: August 2026. This post follows a quarterly refresh cadence given its ties to evolving certificate validity policy and vendor guidance.

Frequently Asked Questions

What is the main takeaway from IoT PKI?

As connected device counts scale into the billions, password-based identity management becomes impractical, and PKI digital certificates become the best option for device authentication, firmware code signing, and encrypted device communication.

Why does this matter for enterprise PKI teams?

PKI teams are responsible for issuing and tracking device identity certificates and firmware signing certificates at IoT scale, and for flagging any device category without certificate-based authentication as a risk.

What risks increase if this topic is handled manually?

Manually tracking certificates across a large IoT device fleet increases the risk of an expired certificate disconnecting many devices simultaneously, or a compromised device remaining active because revocation wasn’t fast enough.

Which teams should own this change?

Security architects design device onboarding around certificate-based identity, platform teams integrate certificate issuance into provisioning and firmware pipelines, PKI administrators track certificates across the fleet, and compliance teams verify PII-handling devices are encrypted.

How does this connect to certificate lifecycle management?

Device identity certificates and firmware code-signing certificates need the same issuance, renewal, and revocation discipline as any other certificate; treating them as part of one certificate lifecycle management program prevents fleet-wide outages from a single overlooked expiry.

How should organizations measure success?

Track the percentage of devices with valid automatically renewed identity certificates, the percentage of firmware releases that are code signed, and how quickly a compromised device’s certificate can be revoked.

What should be audited or monitored regularly?

Regularly audit certificate issuance and expiry dashboards across the device fleet to catch a lapse before it disconnects devices or leaves unsigned firmware in circulation.

How does this topic affect cloud, hybrid, or multi-CA PKI?

Large IoT deployments often issue device certificates from a dedicated CA separate from enterprise IT certificates, and both need centralized certificate discovery so no device or CA is left untracked.

What common mistakes should teams avoid?

Common mistakes include using shared passwords or static keys for device authentication, skipping code signing on firmware updates, and lacking a fast revocation process for compromised devices.

What should be refreshed quarterly?

Review device onboarding for new device categories that need certificate-based identity, confirm certificate validity periods against the current CA/Browser Forum schedule, and re-verify that PII-handling devices remain encrypted end to end.