Zero Trust for Enterprise Devices: A Practical Guide

by . ᧁꫝꪮᦓꪻ May 29, 2025

Acronyms to Know

ZT - Zero Trust

ZTNA - Zero Trust Network Access

EDR - Endpoint Detection and Response

MDM/UEM - Mobile Device Management / Unified Endpoint Management

MFA - Multi-Factor Authentication

SSO - Single Sign-On

IdP - Identity Provider

SIEM - Security Information and Event Management

CA - Certificate Authority

DEP - Apple’s Device Enrollment Program (now known as ADE (Automated Device Enrollment)

AV - Antivirus

mTLS - mutual Transport Layer Security (It’s like shaking hands but you check each other’s ID badge first.)

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What is Zero Trust?

"Never trust, always verify."

Zero Trust is a modern security approach based on the idea that nothing inside or outside your perimeter should be trusted by default. Instead, every request must be authenticated, authorized, and continuously validated.

In enterprise environments, Zero Trust shifts the focus from the network to users, devices, and applications — with continuous evaluation and access control based on trust signals.

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Key Principles

1. Assume breach - every device or user could be compromised

2. Least privilege - give access only to what’s needed

3. Continuous verification - identity, device health, and context must be re-evaluated

4. Context-based enforcement - use real-world signals like device posture and location

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Zero Trust for Devices

Zero Trust applied to endpoints means:

- Devices must be enrolled in your MDM/UEM (ex. Apple’s DEP/ADE + Remote MDM Configuration through Jamf, WorkspaceOne etc.)

- Compliance must be enforced, meaning (but not limited to):

- OS is fully patched

- Disk encryption enabled (e.g. FileVault, Bitlocker)

- AV / EDR software is running and up to date

- Firewall is Active and properly configured

- Access policies should factor in real-time posture

- Non-compliant or unknown devices should be blocked or isolated

Some tools I’ve worked with in this space include [Intune](https://learn.microsoft.com/en-us/mem/intune/), [Jamf](https://www.jamf.com), and [Workspace ONE](https://www.vmware.com/products/workspace-one.html).

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Identity and Authentication

The identity layer is critical to Zero Trust:

- Use a trusted IdP like [Okta](https://www.okta.com) or [Azure AD](https://azure.microsoft.com/en-us/products/active-directory/)

- Or be wild and build your own internal solution.. could be fun!?

- Enforce MFA using strong factors like FIDO2 keys or app-based approval [https://duo.com]

- Issue device certificates when possible to verify machine identity:

Basically, MDM or internal tooling issues a certificate to the device during onboarding.
The certificate is stored in the device’s secure keychain or system store.
When the device tries to connect to a resource (like a VPN, Wi-Fi, internal site, or IdP session), it presents the cert as part of mutual TLS (mTLS) or certificate-based authentication.
The service checks the cert’s validity, issuer, expiration, and sometimes revocation status.
Main Tips: Use short lived certificates, tie cert issuance to MDM enrollment flow, revoke certs when device is wiped, compromised, or offboarded.

- Conditional Access should evaluate the device’s posture and block risky or suspicious sessions

Some orgs also automate session revocation when posture signals change. Ex. if encryption is disabled or antivirus is inactive.

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ZTNA - Beyond VPN

Zero Trust Network Access replaces traditional VPNs with access controls based on identity and device posture.

Device Trust Signals

You’ll want to track things like:

- OS version and patch status

- Disk encryption status (FileVault, BitLocker)

- Active EDR / AV tools

- MDM compliance

- Custom logic using scripts or posture queries

Lightweight tools like [FleetDM](https://fleetdm.com) or native MDM scripts can be used to gather and respond to posture data.

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Frameworks Worth Reading

- [NIST SP 800-207](https://csrc.nist.gov/publications/detail/sp/800-207/final) - foundational Zero Trust architecture

- [CISA Zero Trust Maturity Model](https://www.cisa.gov/resources-tools/resources/zero-trust-maturity-model) - useful for phased rollouts

- [Forrester ZTX](https://go.forrester.com/blogs/introducing-zero-trust-extended-framework/) - original commercial model

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Example Tools and Platforms

Here are some tools commonly used in Zero Trust environments. I’ve worked directly with a few of these and am actively studying others:

- Identity: Okta, Azure AD

- MDM/UEM: Intune, Jamf, Workspace ONE

- EDR: Crowdstrike Falcon [https://www.crowdstrike.com/platform/], Defender for Endpoint [https://learn.microsoft.com/en-us/defender-endpoint/microsoft-defender-endpoint]

- ZTNA: Tailscale

- Automation: Python, scripting, internal workflows

- Visibility: Custom compliance checks and dashboards (I find this to be particularly interesting for in-house tooling)

If you’re building out Zero Trust for your org, focus on tools that integrate well and let you control enforcement based on real-time data.

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Notes on Implementation

Start simple, then layer up. A basic rollout might include:

1. SSO and MFA across critical systems

2. MDM enrollment with enforcement policies

3. Conditional Access that evaluates device trust

4. Monitoring tools for posture, compliance, and anomalies

5. Feedback loop to adjust access dynamically

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Caveats and Challenges

- Too much friction = unhappy users

- Too many overlapping tools = confusion and bloat

- BYOD can be hard to manage

- Older or unmanaged systems might require exceptions or segmentation

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Final Thoughts

Zero Trust isn’t a one-size-fits-all product but rather a strategy and mindset. The key is getting visibility into device posture, enforcing policy through identity and access, and responding quickly to changes in trust.

I’m continuing to explore how to implement this model using existing (paid vs open source) + custom tools - and will share more thoughts, scripts, and workflows over time.

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Written by ᧁꫝꪮᦓꪻ for deepnet.store — building hacker kits, cyber tools, and smarter security practices.