Never trust. Always verify.

Zero Trust Architecture

Identity-first security designed around your real environment, verified continuously.

Why this matters

The old perimeter is gone.

People, devices and data sit everywhere now, so trust has to be earned continuously, not assumed once at the firewall. Zero Trust is a design principle, not a product, and it works best when it is built around how your organisation actually operates.

What we do

We design and implement a Zero Trust model around your real environment: identity-first, segmented, and continuously verified.

Our work includes

  • Zero Trust strategy and reference architecture
  • Identity and network segmentation
  • Continuous authentication and conditional access
  • Secure access and SASE design
  • Cloud and on-prem integration
The outcome

Access that’s earned continuously, not assumed at the perimeter.

Book a health check
How it decides

Every request, evaluated. Every time.

No silent trust. Each access attempt is weighed against who you are, what device you are on, where you are coming from, and how risky the moment looks, then re-checked continuously while the session is open.

IdentityUser, role, groupDeviceCompliant & healthyLocationCountry, networkRiskBehaviour, threat intelEVALUATE EVERY REQUESTZero Trust engineIdentity · Device · Context · RiskMicrosoft Entra Conditional AccessAllowwith session controlsStep-upphishing-resistant MFABlocklog and alertCONTINUOUSLY RE-EVALUATED, NOT JUST AT SIGN-IN
The architecture

Six pillars. One continuously-verified outcome.

Zero Trust is not a single product, it is a set of pillars working together. Here is what delivers each one, and how they connect in your environment.

Identity

Who, on what device, doing what.

Phishing-resistant MFA, Conditional Access, least-privilege roles, just-in-time elevation, and full vaulting of privileged credentials.

Delivered by

Microsoft Entra IDConditional AccessDelinea PAM1Password
Device

No compliance, no access.

Every endpoint is managed, patched, and continuously assessed. Compliance and risk signals feed identity decisions in real time.

Delivered by

Microsoft IntuneDefender for EndpointCrowdStrike FalconJamf
Network

Per-app access, not the whole network.

Replace broad VPN tunnels with Zero Trust Network Access (ZTNA): per-application, per-session, evaluated each time. Web and SaaS go through an SSE.

Delivered by

Netskope NPA (ZTNA)Netskope SWGMicrosoft Entra Internet Access
Applications

Apps brokered, not exposed.

Modern app access through identity-aware proxies and CASB. Legacy apps wrapped, not flat-routed; SaaS posture monitored and controlled.

Delivered by

Microsoft Entra App ProxyNetskope CASBConditional Access for apps
Data

Self-protecting, wherever it travels.

Sensitivity labels and DLP travel with the file. Posture management finds where data lives, and AI guardrails control where it goes next.

Delivered by

Microsoft PurviewNetskope DLPCyera DSPMSkope AI
Visibility & analytics

See it, correlate it, act on it.

Telemetry from every pillar feeds a single analytics plane. Detections trigger automated response, not someone reading dashboards on Monday.

Delivered by

Microsoft SentinelDefender XDRCrowdStrike NG-SIEM
The shift

From "trust the tunnel" to per-app, evaluated each time.

The biggest practical Zero Trust win is retiring the broad VPN tunnel. Same user experience, far less risk surface.

Before

Traditional VPN

One tunnel, full network access. Trust assumed for the whole session.

  • One credential away from the whole network
  • No device posture check after connect
  • Lateral movement, once you are in
  • Slow, painful user experience
After

Zero Trust Network Access

Per-application access, evaluated continuously. Identity, device and context every session.

  • One app at a time, evaluated each time
  • Device compliance enforced every session
  • No network reachable beyond what you need
  • Faster than a VPN, every time
The journey

A 12 to 24 month journey, with foundations live in 90 days.

We sequence the work so the highest-value controls go live first, then expand into network, applications and data.

90
days
Phase 01

Identity foundations

Phishing-resistant MFA everywhere. Conditional Access enforced. Device compliance required to sign in. Privileged accounts vaulted.

6–12
mths
Phase 02

Network and applications

Retire the VPN. Move to ZTNA per-app. Modernise app access via identity-aware proxies. CASB across SaaS. SWG inline for web.

12–24
mths
Phase 03

Data and automation

Self-protecting data with labels and DLP. DSPM closes the visibility gap. Analytics correlated; high-confidence detections respond automatically.

Why Cornerstone?

We are not another managed service you cannot leave. We design, implement and hand over secure systems your team can run, with the documentation and clarity to stay in control. No lock-ins, just results.

Zero Trust

Trust nothing by default. Verify everything explicitly.

Zero Trust without the buzzword.

What does Zero Trust actually mean?

A design principle: never assume any user, device or network is trusted just because it is "inside". Every access decision is verified explicitly using identity, device health, and context.

Is Zero Trust a product?

No, despite the vendor marketing. Zero Trust is an architecture and a set of principles. You deliver it through Conditional Access (Entra), endpoint compliance (Intune, Defender, CrowdStrike), modern access (Netskope ZTNA), and least-privilege identity design.

Where do we start with Zero Trust?

With identity. If MFA is everywhere, Conditional Access is enforced, and devices must be compliant to sign in, you have the foundations. Everything else (network, data, applications) builds on that.

Does Zero Trust mean replacing the VPN?

Often yes, eventually. Zero Trust Network Access (ZTNA, in our stack Netskope NPA) replaces broad VPN tunnels with per-application access, evaluated each time. Better security, better user experience, less attack surface.

How does Zero Trust apply to data?

Sensitivity labels and DLP make data self-protecting: encrypted by default, with access rules that travel with the file. Combined with Conditional Access, even a stolen file is unreadable to an unauthorised user on an untrusted device.

How long does the journey take?

Most organisations take 12 to 24 months to reach a mature Zero Trust posture, depending on where they start. The foundational identity controls are usually deliverable in the first 90 days.