- Purple
- Enterprise WiFi security and authentication: a complete guide
- Microsoft Cloud PKI for WiFi: EAP-TLS certificate deployment with Intune and Entra ID
Microsoft Cloud PKI for WiFi: EAP-TLS certificate deployment with Intune and Entra ID
You will be able to decide whether Microsoft Cloud PKI, a Cloud PKI root or bring your own CA (BYOCA) fits your estate. You can then deploy EAP-TLS WiFi certificates to Intune-managed devices without NDES. The guide also covers making RADIUS trust the chain, revoking certificates through the CRL and fixing the eight most common failures.
Part of our core series: Enterprise WiFi security guide →
- What does Microsoft Cloud PKI do for WiFi authentication?
- How the Cloud PKI CA hierarchy works
- How Cloud PKI compares with SCEP with NDES and PKCS
- What do you need before you deploy Cloud PKI for EAP-TLS?
- How do you set up Cloud PKI certificates for WiFi?
- Step 1: create the root CA, or bring your own
- Step 2: create the issuing CA
- Step 3: deploy trusted certificate profiles
- Step 4: create the SCEP certificate profile
- Step 5: make the RADIUS server trust Cloud PKI
- Step 6: build the WiFi profile
- How does revocation work with Cloud PKI?
- How do you check Cloud PKI WiFi authentication works?
- What goes wrong with Cloud PKI EAP-TLS, and how do you fix it?
- Cloud PKI or SCEP with NDES: which should you choose?
- What does Cloud PKI cost, and what do you get back?
- Worked scenario: a 30-property hotel group
- Worked scenario: a 250-store retail chain
- Where Purple fits
- Frequently asked questions
- Can Microsoft Cloud PKI issue WiFi certificates?
- Do I still need NDES with Cloud PKI?
- How does the RADIUS server trust Cloud PKI certificates?
- How does revocation work with Cloud PKI?
- Should I choose Cloud PKI or SCEP with NDES?
- How is Microsoft Cloud PKI licensed?
- Can I keep my existing on-premises root CA with Cloud PKI?
- Does Cloud PKI work with my existing access points?

Yes. Microsoft Cloud PKI, the hosted certificate authority in the Intune Suite, issues EAP-TLS WiFi certificates to Intune-managed devices. A SCEP certificate profile requests them directly, so you need no NDES server, certificate connector or on-premises CA. Your RADIUS server trusts the imported Cloud PKI root and checks each certificate against the CRL the service publishes.
What does Microsoft Cloud PKI do for WiFi authentication?
EAP-TLS (Extensible Authentication Protocol - Transport Layer Security) is the 802.1X method in which both sides prove their identity with certificates. IEEE 802.1X is the port-based access control standard behind WPA2-Enterprise and WPA3-Enterprise. The access point passes each connection attempt to a RADIUS server, the authentication server that accepts or rejects the device. With EAP-TLS there is no password to phish and no shared key to leak. Each device holds its own private key and certificate.
The hard part has always been the PKI (public key infrastructure) behind it. Getting certificates onto Intune-managed devices traditionally needed four things:
- an Active Directory Certificate Services (AD CS) issuing CA
- an NDES (Network Device Enrollment Service) server
- the Intune Certificate Connector
- a reverse proxy or Microsoft Entra application proxy to publish NDES to the internet
Each one needs patching, backups and monitoring.
Microsoft Cloud PKI replaces that stack with a certificate authority hosted in your Intune tenant. Devices request certificates over SCEP (Simple Certificate Enrollment Protocol), and Cloud PKI answers those requests itself. It validates each request against Intune, signs the certificate and returns it. The device generates its private key locally, and the key never leaves it.
For Entra ID-joined fleets, this removes the last on-premises dependency in the certificate chain. Devices that have never seen a domain controller can still get a WiFi certificate.
How the Cloud PKI CA hierarchy works
Cloud PKI uses a two-tier hierarchy. A root CA signs one or more issuing CAs, and the issuing CA signs device certificates. Microsoft holds the CA signing keys in hardware security modules (HSMs), so you never manage key material.
You choose one of two anchors:
- Cloud PKI root. Microsoft hosts both the root and the issuing CA in your tenant. This is the simplest option for a greenfield Entra ID estate.
- Bring your own CA (BYOCA). You create a Cloud PKI issuing CA, download its certificate signing request and sign it with your existing private root, such as an AD CS root. Anything that already trusts that root then trusts the new issuing CA's chain.
You set extended key usages (EKUs) when you create each CA. WiFi client certificates need the Client Authentication EKU, so include it at both tiers. Plan this carefully, because the EKUs are fixed when the CA is created.
One boundary matters for design. Cloud PKI issues certificates to Intune-managed devices through SCEP. It is not built to issue your RADIUS server's own certificate, so that certificate normally comes from a public CA or your existing PKI.
How Cloud PKI compares with SCEP with NDES and PKCS
| Cloud PKI (SCEP) | SCEP with NDES | PKCS | |
|---|---|---|---|
| CA hosting | Microsoft-hosted in your Intune tenant | Your AD CS or third-party CA | Your AD CS or third-party CA |
| On-premises servers | None | Issuing CA, NDES server, connector host | Issuing CA, connector host |
| Internet-published component | None | NDES, via reverse proxy or application proxy | None |
| Where the private key is generated | On the device | On the device | On the CA side, delivered to the device as a PFX |
| Fit for Entra ID-only fleets | Native | Works, but keeps on-premises dependencies | Works, but keeps on-premises dependencies |
| Revocation | Revoke in the Intune admin centre, published by CRL | Through the connector and your CA's CRL | Through the connector and your CA's CRL |
| Licence model | Intune Suite or Cloud PKI add-on, per seat | Windows Server licences plus Intune | Windows Server licences plus Intune |
| Who it suits | Cloud-first estates retiring on-premises PKI | Estates with a mature AD CS team and a long CA roadmap | Cases that need the same key on more than one platform, such as S/MIME |
Our separate guide to Intune certificate deployment with SCEP and PKCS covers the two on-premises routes in depth.
What do you need before you deploy Cloud PKI for EAP-TLS?
Check these six items before you create anything. Each one maps to a failure in the troubleshooting section below.
- Licensing. An Intune Plan 1 subscription plus either the Microsoft Intune Suite or the standalone Cloud PKI add-on.
- Permissions. The Intune Administrator role, or a custom role with the Cloud PKI permissions.
- Enrolled devices. Windows, macOS, iOS/iPadOS or Android devices enrolled in Intune, grouped in Microsoft Entra ID security groups.
- An EAP-TLS-capable RADIUS server. It must let you import CA certificates, reach the Cloud PKI CRL over HTTP, and map certificate identities to Entra ID objects. Microsoft NPS (Network Policy Server) looks up accounts in on-premises Active Directory, so cloud-only devices fail there.
- A RADIUS server certificate. You also need the root and any intermediate certificates that issued it, because devices must validate the server.
- 802.1X-capable access points. These must broadcast a WPA2-Enterprise or WPA3-Enterprise SSID pointed at your RADIUS server.
On the access point side, every major platform supports 802.1X. That includes Cisco Meraki, HPE Aruba, Ruckus, Juniper Mist, Ubiquiti UniFi, Cambium, Extreme and Fortinet. For a vendor-specific walkthrough, see Configuring 802.1X on Juniper Mist with cloud RADIUS.
How do you set up Cloud PKI certificates for WiFi?
The sequence below summarises the build. Use Microsoft's Cloud PKI documentation on Microsoft Learn for the current screens and field-by-field steps, because the admin centre layout changes between releases.
Step 1: create the root CA, or bring your own
In the Intune admin centre, create a root CA under tenant administration. Choose the key size, validity period and EKUs, including Client Authentication.
For BYOCA, skip the root. Create the issuing CA as a BYOCA type and export its certificate signing request. Sign the request on your private CA using a template that includes Client Authentication, then upload the signed certificate and its chain.
Step 2: create the issuing CA
Create an issuing CA anchored to the root from step 1. Its EKUs must include Client Authentication. Once created, its properties page shows three things you will need later:
- the SCEP URI
- the CA certificate download
- the CRL distribution point
Step 3: deploy trusted certificate profiles
Download the root and issuing CA certificates. Create one trusted certificate profile for each, per platform. Assign them to the same groups that will receive the SCEP and WiFi profiles.
Devices need this chain before the SCEP profile can succeed. Create a further trusted certificate profile for the CA that issued your RADIUS server certificate, if devices do not already trust it.
Step 4: create the SCEP certificate profile
Create a SCEP certificate profile per platform and point it at Cloud PKI. These are the key decisions:
- SCEP server URL. Paste the SCEP URI from the issuing CA exactly as shown. Leave its placeholder text unedited, because Intune resolves it at issuance.
- Root certificate. Select the trusted certificate profile for the Cloud PKI root, not the issuing CA.
- Certificate type. Choose device certificates for shared devices such as front-desk tablets or store handhelds. Choose per-person certificates where staff carry their own laptop and you want policy tied to the individual.
- Subject and subject alternative name (SAN). Include an identifier your RADIUS server can map to Entra ID. Examples are the Entra device ID variable
{{AAD_Device_ID}}or the UPN variable{{UserPrincipalName}}. - Key usage and EKU. Set Digital signature and Key encipherment, with Client Authentication.
- Key storage on Windows. Enrol to the TPM (Trusted Platform Module) key storage provider, so the private key is hardware-bound and non-exportable.
- Renewal threshold. Set the percentage of remaining lifetime at which Intune renews, so certificates never lapse unnoticed.
Step 5: make the RADIUS server trust Cloud PKI
Import both the Cloud PKI root and issuing CA certificates into your RADIUS server's trusted CA store. Importing only the root is the most common cause of "unknown CA" rejections.
Enable CRL checking, and allow the RADIUS server outbound HTTP access to the CRL distribution point listed in each certificate. With BYOCA, the RADIUS server may already trust your root, so you add only the new issuing CA certificate.
If Purple's cloud RADIUS authenticates your Staff WiFi, your Purple account team will confirm how the Cloud PKI chain is loaded for your tenant.
Step 6: build the WiFi profile
Create an Intune WiFi profile with enterprise security and EAP-TLS as the EAP type. Set three fields:
- Client authentication certificate. Select the SCEP profile from step 4.
- Root certificates for server validation. Select the trusted certificate profile for your RADIUS server's issuing root.
- Certificate server names. Enter names that match the RADIUS server certificate exactly.
Assign the profile to the same groups as the SCEP and trusted certificate profiles.
How does revocation work with Cloud PKI?
You revoke Cloud PKI certificates from the issuing CA in the Intune admin centre. Open the list of issued certificates, select the device's certificate and revoke it. Cloud PKI then publishes the change to its CRL (certificate revocation list), which sits at the HTTP distribution point embedded in every certificate it issues.
Your RADIUS server enforces the revocation, not Intune. It downloads the CRL and rejects any certificate whose serial number appears on it.
Most RADIUS servers cache a CRL until its next-update time. A revoked device can therefore keep connecting until the RADIUS server fetches a fresh list. Close that window in three ways:
- Revoke explicitly. Do not rely on removing a profile assignment or deleting a device record. Revoke the certificate itself as part of your joiners, movers, leavers (JML) process.
- Pair revocation with identity checks. If your RADIUS service checks Entra ID account or device status at each authentication, disabling the account blocks access before the CRL refreshes.
- Watch CRL retrieval. Alert on failed CRL downloads. A RADIUS server holding a stale CRL either keeps admitting revoked devices or rejects every device, depending on its failure policy.
Got questions about your specific setup?
Our team works with venue operators, IT managers, and network engineers across 80,000 venues. Book a 20-minute call and we will show you how others like you solved it.
How do you check Cloud PKI WiFi authentication works?
Pilot with a test group of five to 10 devices across each platform you support. Confirm five things:
- Profile status. The trusted certificate, SCEP and WiFi profiles all report success in Intune device configuration reporting.
- Certificate on the device. On Windows, the certificate appears in the personal store with the expected subject, SAN and Client Authentication EKU. Its chain should build to the Cloud PKI root.
- Issuance record. The certificate appears in the issuing CA's list of issued certificates in the Intune admin centre.
- RADIUS logs. The authentication log shows EAP-TLS success, the expected identity and a valid chain.
- Revocation test. Revoke one test certificate. Once the RADIUS server picks up the new CRL, confirm that the device is rejected.
Run the revocation test before you go live. It is the only check that proves your RADIUS server can reach the CRL.
What goes wrong with Cloud PKI EAP-TLS, and how do you fix it?
| Symptom | Likely cause | Fix |
|---|---|---|
| SCEP profile stuck in error or pending | Trusted certificate profiles not assigned to the same group, or the SCEP profile references the issuing CA instead of the root | Assign root and issuing trusted profiles to the same groups, and select the root in the SCEP profile |
| Certificate issued, RADIUS rejects with "unknown CA" | Only the root imported into RADIUS | Import the issuing CA certificate as well |
| Every device rejected after go-live | RADIUS cannot reach the CRL distribution point and fails closed | Allow outbound HTTP from RADIUS to the CRL host |
| Android devices refuse to connect | No server validation set; Android 11 and later require it | Deploy the RADIUS server's root as a trusted profile and set certificate server names |
| Windows prompts staff to trust the server | Server names in the WiFi profile do not match the RADIUS certificate | Correct the server names to match the certificate exactly |
| NPS rejects Entra ID-joined devices | NPS looks for an on-premises Active Directory account that does not exist | Use a RADIUS service that maps certificates to Entra ID objects |
| Revoked device still connects | RADIUS holding a cached CRL | Pair revocation with an Entra ID account or device disable, and review CRL caching |
| Certificate lacks Client Authentication | Issuing CA created without that EKU | Create a new issuing CA with Client Authentication and repoint the SCEP profile |
If failures cluster in particular rooms or floors while the same devices authenticate elsewhere, the fault is radio coverage, not PKI. EAP-TLS exchanges more packets than a pre-shared key handshake, so marginal signal shows up as timeouts. WiFi Site Surveys: A Practical Planning Guide covers how to find those gaps.
Cloud PKI or SCEP with NDES: which should you choose?
Base the decision on what you already run and what you plan to retire.
| Your situation | Recommendation | Why |
|---|---|---|
| Entra ID-joined fleet, no AD CS | Cloud PKI with a Cloud PKI root | No on-premises PKI to build or run |
| AD CS in place, NDES servers due for an OS refresh | Cloud PKI with BYOCA | Keeps your existing root trust and retires NDES and the connector |
| AD CS team with a long-term CA roadmap and other certificate templates | SCEP with NDES, review at the next server refresh | Existing investment already covers non-WiFi use cases |
| Need the same key pair on several devices, such as S/MIME | PKCS for that use case, Cloud PKI for WiFi | PKCS delivers exportable keys; WiFi certificates should stay device-bound |
| Hybrid-joined devices on NPS today, moving to Entra ID join | Cloud PKI plus a cloud RADIUS service | NPS lookups break once devices leave Active Directory |
Regulated estates in Healthcare often keep AD CS for other workloads. For them, BYOCA is usually the fit, because it keeps one root of trust across the organisation. Rail operators issuing certificates to onboard staff tablets on Trains tend to fit the Cloud PKI root route. Those devices are cloud-managed from day one.
What does Cloud PKI cost, and what do you get back?
Microsoft licenses Cloud PKI per seat, per month. It comes either within the Intune Suite or as a standalone add-on, on top of Intune Plan 1. Check Microsoft's current price list, because bundling changes.
Weigh that against what the on-premises route costs you:
- Windows Server licences and virtual machines for the issuing CA, NDES and connector hosts
- the reverse proxy or application proxy publishing NDES
- CA database backups
- patching and certificate template administration
The return is fewer servers, no internet-published NDES endpoint, and device-bound keys on every platform you manage.
Worked scenario: a 30-property hotel group
Situation. A group of 30 hotels ran 900 Entra ID-joined laptops and front-desk tablets on a staff SSID secured with one shared pre-shared key. Rotating that key each quarter meant touching every device at every property. A lost tablet left the key exposed until the next rotation.
What was done. IT created a Cloud PKI root and issuing CA, then issued TPM-backed device certificates through SCEP. A cloud RADIUS service validated the chain and checked the CRL. The group ran an EAP-TLS SSID alongside the old one for the pilot, moved properties in waves, then switched off the pre-shared key network.
Outcome. The scenario arithmetic is straightforward:
- Shared secrets on the staff network fall from one to zero.
- Quarterly key rotation across 30 properties stops entirely.
- A lost tablet becomes one certificate revocation instead of a re-key of 900 devices.
- No on-premises CA, NDES server or connector is needed.
Worked scenario: a 250-store retail chain
Situation. A retail chain issued WiFi certificates to 4,000 store handhelds and laptops through AD CS and two NDES servers. The Intune Certificate Connector ran on a third server. All three servers were due for operating system replacement, and NDES was published through an application proxy.
What was done. The team created a Cloud PKI issuing CA as BYOCA and signed it with the existing AD CS root. The RADIUS server already trusted that root, so only the new issuing CA certificate was imported. SCEP profiles moved to Cloud PKI one store group at a time. Existing certificates stayed valid until renewal, which preserved rollback.
Outcome. The chain retired three servers: two NDES and one connector host. It also removed the internet-published NDES endpoint. No root re-trust was needed on RADIUS or on any device. The AD CS root stayed in place for other workloads.
Where Purple fits
Purple Staff WiFi uses Identity-Based Networks with cloud RADIUS, connected to Microsoft Entra ID, Okta or Google Workspace. Purple is hardware-agnostic across Cisco Meraki, HPE Aruba, Ruckus, Juniper Mist, Ubiquiti UniFi, Cambium, Extreme and Fortinet. Why your next WiFi upgrade doesn't need new hardware explains why moving to certificate-based staff access rarely means replacing access points.
Purple runs at 80,000+ live venues (Purple data) with 99.999% uptime, and is ISO 27001 certified. Keep staff and visitors on separate networks: certificate-based Staff WiFi for devices you manage, and Guest WiFi for everyone else.
Frequently asked questions
Can Microsoft Cloud PKI issue WiFi certificates?
Yes. Cloud PKI issues client authentication certificates to Intune-managed Windows, macOS, iOS/iPadOS and Android devices through a SCEP certificate profile. Those certificates authenticate devices to WPA2-Enterprise or WPA3-Enterprise networks using EAP-TLS. Your issuing CA must include the Client Authentication EKU, and your RADIUS server must trust the Cloud PKI root and issuing CA. Cloud PKI does not normally issue the RADIUS server's own certificate. That certificate comes from a public CA or your existing PKI.
Do I still need NDES with Cloud PKI?
No. Cloud PKI answers SCEP requests itself, so you need no NDES server, no Intune Certificate Connector and no reverse proxy publishing NDES to the internet. The SCEP profile in Intune points directly at the SCEP URI shown on your Cloud PKI issuing CA. If you use the bring-your-own-CA option, your private root signs the Cloud PKI issuing CA once. After that, device enrolment never touches your on-premises servers.
How does the RADIUS server trust Cloud PKI certificates?
You import the Cloud PKI root and issuing CA certificates into the RADIUS server's trusted CA store. Download both from the Intune admin centre. Import both, because importing only the root causes "unknown CA" rejections. The RADIUS server also needs outbound HTTP access to the CRL distribution point in each certificate, so it can check revocation. For Entra ID-joined devices, it must map certificate identities to Entra ID rather than on-premises Active Directory.
How does revocation work with Cloud PKI?
You revoke a certificate from the issuing CA in the Intune admin centre, and Cloud PKI publishes the change to its CRL. Your RADIUS server downloads that CRL and rejects revoked certificates. Because RADIUS servers cache CRLs, a revoked device may connect until the next refresh. Close that gap by also disabling the Entra ID account or device, provided your RADIUS service checks identity status at each authentication.
Should I choose Cloud PKI or SCEP with NDES?
Choose Cloud PKI if you run an Entra ID-joined fleet or plan to retire on-premises PKI servers. It removes the issuing CA, NDES and connector hosts. Keep SCEP with NDES if you have a mature AD CS team, a long-term CA roadmap and other certificate templates. If your NDES servers are due for refresh, Cloud PKI with BYOCA keeps your existing root trust and still retires NDES.
How is Microsoft Cloud PKI licensed?
Cloud PKI is licensed per seat, per month, on top of Intune Plan 1. It comes either as part of the Microsoft Intune Suite or as a standalone Cloud PKI add-on. Check Microsoft's current price list before budgeting, as bundles change. Set the licence cost against the Windows Server licences, virtual machines, proxy publishing and patching effort that an AD CS, NDES and connector stack requires.
Can I keep my existing on-premises root CA with Cloud PKI?
Yes, through the bring-your-own-CA option. You create a Cloud PKI issuing CA, export its certificate signing request and sign it with your existing private root, such as AD CS. Anything that already trusts that root, including your RADIUS server and devices, then trusts the new chain. You add only the issuing CA certificate. You can migrate SCEP profiles group by group while existing certificates stay valid until renewal.
Does Cloud PKI work with my existing access points?
Yes, as long as your access points support 802.1X with WPA2-Enterprise or WPA3-Enterprise. Cloud PKI only affects the certificates on devices and the trust on your RADIUS server. The access points simply forward authentication to RADIUS. Cisco Meraki, HPE Aruba, Ruckus, Juniper Mist, Ubiquiti UniFi, Cambium, Extreme and Fortinet all support this. Purple's Staff WiFi runs across all eight as a hardware-agnostic cloud overlay.
Key Definitions
EAP-TLS
Extensible Authentication Protocol - Transport Layer Security, defined in RFC 5216 and updated for TLS 1.3 in RFC 9190. Client and server authenticate each other with X.509 certificates inside an 802.1X exchange, so no password or shared key is used.
This is the EAP type you select in the Intune WiFi profile. It removes the shared pre-shared key that teams otherwise rotate across every device and property.
IEEE 802.1X
The IEEE standard for port-based network access control. It defines how a supplicant, an authenticator (the access point) and an authentication server exchange EAP messages before network access is granted.
WPA2-Enterprise and WPA3-Enterprise SSIDs rely on it. Your access points must support it and forward authentication to your RADIUS server.
RADIUS
Remote Authentication Dial-In User Service, specified in RFC 2865. It carries authentication requests from the access point to a server that accepts or rejects the device.
The RADIUS server enforces trust and revocation, not Intune. It must import the Cloud PKI chain, reach the CRL and map certificate identities to Entra ID objects.
SCEP
Simple Certificate Enrollment Protocol, documented in RFC 8894. A device generates its key pair locally and sends a certificate signing request to a CA, which returns the signed certificate.
Cloud PKI answers SCEP requests itself, so the Intune SCEP certificate profile points directly at the issuing CA's SCEP URI with no NDES server.
NDES
Network Device Enrollment Service, the Windows Server role service in Active Directory Certificate Services that implements SCEP for an AD CS issuing CA.
The traditional Intune route needs NDES, the Intune Certificate Connector and a proxy publishing NDES to the internet. Cloud PKI removes all three.
Certificate revocation list (CRL)
A signed list of revoked certificate serial numbers defined in the X.509 profile, RFC 5280. It is published at the CRL distribution point embedded in each certificate and carries a next-update time.
RADIUS servers cache the CRL until its next-update time, so a revoked device can keep connecting. Failed CRL retrieval can also reject every device.
Extended key usage (EKU)
An X.509 v3 certificate extension, defined in RFC 5280, that restricts a certificate's purposes. Client Authentication is the purpose identified by OID 1.3.6.1.5.5.7.3.2.
WiFi client certificates need Client Authentication at both the root and issuing CA. EKUs are fixed at CA creation, so omitting it forces a new issuing CA.
Bring your own CA (BYOCA)
A Cloud PKI option in which you create a Cloud PKI issuing CA, export its certificate signing request and sign it with your existing private root, such as an AD CS root.
It suits estates that keep AD CS for other workloads. RADIUS and devices that already trust the root need only the new issuing CA certificate.
Trusted Platform Module (TPM)
A hardware security chip specified by the Trusted Computing Group TPM 2.0 Library, published as ISO/IEC 11889. It generates and stores keys that cannot be exported.
Enrolling Windows SCEP certificates to the TPM key storage provider binds the private key to the device, so a copied certificate cannot be reused elsewhere.
PKCS certificate profile
An Intune certificate route based on the PKCS #12 (PFX) format, standardised in RFC 7292. The key pair is generated on the CA side and delivered to the device inside a password-protected file.
PKCS suits cases needing the same key on several devices, such as S/MIME. WiFi certificates should stay device-bound, so Cloud PKI over SCEP fits better.
Hardware security module (HSM)
A tamper-resistant device that generates, stores and uses cryptographic keys, commonly validated against NIST FIPS 140. Signing operations run inside the module and keys never leave it.
Microsoft holds Cloud PKI CA signing keys in HSMs, so your team never manages, backs up or protects CA key material.
Worked Examples
A group of 30 hotels runs 900 Entra ID-joined laptops and front-desk tablets on a staff SSID secured with one shared pre-shared key. Quarterly rotation means touching every device at every property, and a lost tablet exposes the key until the next rotation. How should IT move to certificates?
IT created a Cloud PKI root and issuing CA, because the fleet was Entra ID-joined with no AD CS to preserve. TPM-backed device certificates were issued through SCEP, so each private key stayed bound to its device. A cloud RADIUS service validated the chain and checked the CRL. The group ran an EAP-TLS SSID alongside the old network for the pilot, moved properties in waves, then switched off the pre-shared key network. Shared secrets fell from one to zero, quarterly rotation stopped, and a lost tablet became one certificate revocation instead of a re-key of 900 devices. No on-premises CA, NDES server or connector was needed.
A 250-store retail chain issues WiFi certificates to 4,000 handhelds and laptops through AD CS, two NDES servers and a third server running the Intune Certificate Connector. All three are due for operating system replacement, and NDES is published through an application proxy. What is the lowest-risk move?
The team created a Cloud PKI issuing CA as BYOCA and signed it with the existing AD CS root. Because RADIUS already trusted that root, only the new issuing CA certificate was imported, and no device needed a new root. SCEP profiles moved to Cloud PKI one store group at a time. Existing certificates stayed valid until renewal, which preserved rollback throughout. The chain retired three servers, two NDES and one connector host, and removed the internet-published NDES endpoint. The AD CS root stayed in place for other workloads, so certificate trust elsewhere was unaffected.
After go-live, certificates appear on devices and in the issuing CA's list, but RADIUS rejects them with "unknown CA". Days later, every device is rejected at once. What is wrong?
The first symptom points to RADIUS holding only the Cloud PKI root. Importing the issuing CA certificate as well completes the chain, which is the most common fix for "unknown CA" rejections. The second symptom means RADIUS cannot reach the CRL distribution point and is failing closed. Allowing outbound HTTP from RADIUS to the CRL host restores authentication. Alerting on failed CRL downloads stops a repeat, because a stale CRL either admits revoked devices or rejects all of them. A revocation test during the pilot would have exposed the blocked CRL path before go-live.
Frequently asked questions
Can Microsoft Cloud PKI issue WiFi certificates?
Yes. Cloud PKI issues client authentication certificates to Intune-managed Windows, macOS, iOS/iPadOS and Android devices through a SCEP certificate profile. Those certificates authenticate devices to WPA2-Enterprise or WPA3-Enterprise networks using EAP-TLS. Your issuing CA must include the Client Authentication EKU, and your RADIUS server must trust the Cloud PKI root and issuing CA. Cloud PKI does not normally issue the RADIUS server's own certificate. That certificate comes from a public CA or your existing PKI.
Do I still need NDES with Cloud PKI?
No. Cloud PKI answers SCEP requests itself, so you need no NDES server, no Intune Certificate Connector and no reverse proxy publishing NDES to the internet. The SCEP profile in Intune points directly at the SCEP URI shown on your Cloud PKI issuing CA. If you use the bring-your-own-CA option, your private root signs the Cloud PKI issuing CA once. After that, device enrolment never touches your on-premises servers.
How does the RADIUS server trust Cloud PKI certificates?
You import the Cloud PKI root and issuing CA certificates into the RADIUS server's trusted CA store. Download both from the Intune admin centre. Import both, because importing only the root causes "unknown CA" rejections. The RADIUS server also needs outbound HTTP access to the CRL distribution point in each certificate, so it can check revocation. For Entra ID-joined devices, it must map certificate identities to Entra ID rather than on-premises Active Directory.
How does revocation work with Cloud PKI?
You revoke a certificate from the issuing CA in the Intune admin centre, and Cloud PKI publishes the change to its CRL. Your RADIUS server downloads that CRL and rejects revoked certificates. Because RADIUS servers cache CRLs, a revoked device may connect until the next refresh. Close that gap by also disabling the Entra ID account or device, provided your RADIUS service checks identity status at each authentication.
Should I choose Cloud PKI or SCEP with NDES?
Choose Cloud PKI if you run an Entra ID-joined fleet or plan to retire on-premises PKI servers. It removes the issuing CA, NDES and connector hosts. Keep SCEP with NDES if you have a mature AD CS team, a long-term CA roadmap and other certificate templates. If your NDES servers are due for refresh, Cloud PKI with BYOCA keeps your existing root trust and still retires NDES.
How is Microsoft Cloud PKI licensed?
Cloud PKI is licensed per seat, per month, on top of Intune Plan 1. It comes either as part of the Microsoft Intune Suite or as a standalone Cloud PKI add-on. Check Microsoft's current price list before budgeting, as bundles change. Set the licence cost against the Windows Server licences, virtual machines, proxy publishing and patching effort that an AD CS, NDES and connector stack requires.
Can I keep my existing on-premises root CA with Cloud PKI?
Yes, through the bring-your-own-CA option. You create a Cloud PKI issuing CA, export its certificate signing request and sign it with your existing private root, such as AD CS. Anything that already trusts that root, including your RADIUS server and devices, then trusts the new chain. You add only the issuing CA certificate. You can migrate SCEP profiles group by group while existing certificates stay valid until renewal.
Does Cloud PKI work with my existing access points?
Yes, as long as your access points support 802.1X with WPA2-Enterprise or WPA3-Enterprise. Cloud PKI only affects the certificates on devices and the trust on your RADIUS server. The access points simply forward authentication to RADIUS. Cisco Meraki, HPE Aruba, Ruckus, Juniper Mist, Ubiquiti UniFi, Cambium, Extreme and Fortinet all support this. Purple's Staff WiFi runs across all eight as a hardware-agnostic cloud overlay.
Sources
- Microsoft Learn: Overview of Microsoft Cloud PKI for Intune
- Microsoft Learn: Use certificates for authentication in Microsoft Intune
- RFC 5216: The EAP-TLS authentication protocol
- RFC 8894: Simple Certificate Enrolment Protocol
- RFC 5280: X.509 certificate and CRL profile
- RFC 2865: Remote Authentication Dial In User Service (RADIUS)
Continue reading in this series
Configuring 802.1X on Juniper Mist with cloud RADIUS
You will be able to configure a WPA2 or WPA3-Enterprise WLAN on Juniper Mist that authenticates against cloud RADIUS, decide between UDP RADIUS, RadSec and a Mist Edge proxy, and map RADIUS attributes to dynamic VLANs. You will also know where Mist's client insights timeline and Marvis show exactly where a failed authentication broke.
iOS and macOS 802.1X troubleshooting: a deployment checklist for Intune, Jamf and Entra ID
Use this checklist to diagnose why iPhones, iPads and Macs fail 802.1X on Intune or Jamf Pro. Each failure maps to one of four causes: server trust, identity certificate, macOS mode or Entra ID group scoping. You will confirm the cause from eapolclient and RADIUS logs, apply the fix and stage future certificate rotations.
Intune WiFi profile server trust: certificate server names and root CA checklist for Entra ID
You will be able to configure the server validation half of an Intune WiFi profile so EAP-TLS and PEAP connect on Windows, Apple and Android. You will match certificate server names to the RADIUS certificate, deploy the correct root CA, align Entra ID group assignments, and stage certificate renewals before they silently break connections.
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