Identity-first zero trust: why CISOs must center machine identities

At a glance

What this is: This is an identity-first Zero Trust analysis arguing that CISOs should treat identity as the primary decision point for security, with machine identities and privileged access now central to the risk model.

Why it matters: It matters because IAM, NHI, and security architecture teams have to govern human and non-human access as a single attack surface, not separate operational silos.

By the numbers:

• The average staff member has more than 30 digital identities, and the total of non-human identities outnumbers human identities by as much as 45-to-1.
• The average organization expects identities to surge by 3x in the next 12 months.
• 93% of organizations have experienced at least two identity-related breaches.
• 60% of breaches now involve valid credentials.

👉 Read CyberArk's analysis of how CISOs can use identity to advance Zero Trust

Context

Identity-first Zero Trust starts with a simple reality: access decisions are now made through identities, not through a protected perimeter. That includes both human users and non-human identities such as service accounts, API keys, tokens, certificates, and machine workloads. When those identities are not continuously governed, attackers can move through systems using legitimate access rather than exploit chains.

The article frames this shift as a CISO-level responsibility because identity has moved from an IAM operations topic to a core security architecture issue. That is the right starting point for modern NHI governance. Most enterprise programs still split human identity controls, privileged access, and machine identity management into separate processes, which leaves gaps between ownership, visibility, and enforcement.

Key questions

Q: How should security teams govern non-human identities in zero trust environments?

A: They should treat non-human identities as first-class identities with owners, lifecycle state, privilege scope, and revocation paths. The practical goal is to make access task-scoped, short-lived where possible, and continuously reviewable. If machine identities are managed as exceptions, Zero Trust controls will not reflect how modern systems actually authenticate and operate.

Q: Why do non-human identities create a larger risk than many human accounts?

A: Non-human identities often authenticate silently, persist longer than the workloads they support, and are reused across pipelines or services. That combination increases blast radius when a secret, certificate, or token is exposed. The risk is not just volume, but the difficulty of seeing, owning, and revoking machine access quickly.

Q: What is the difference between JIT access and zero standing privilege for NHI governance?

A: JIT access gives time-limited elevation when a task requires it, while zero standing privilege removes persistent access entirely. For NHI governance, JIT can reduce exposure windows, but ZSP goes further by eliminating dormant admin rights. Teams usually need both, plus strong lifecycle controls, to keep machine access constrained.

Q: When does identity-based Zero Trust fail to stop attackers?

A: It fails when identity records are stale, privileges are excessive, or secrets remain valid after the business no longer needs them. In that case, attackers can use legitimate authentication paths and blend into normal operations. Zero Trust depends on current identity state, not just on the presence of policy language.

Technical breakdown

Why identity becomes the control plane in Zero Trust

Zero Trust works only when every request is evaluated against identity, device, context, and privilege before access is granted. In practice, identity becomes the decision point because an attacker who steals valid credentials can appear legitimate to downstream systems. That problem is harder with non-human identities, since workloads and automation often authenticate silently and at high frequency. Dynamic controls such as adaptive authentication, least privilege, JIT access, and ZSP only work when identity data is accurate and lifecycle state is current. If identity records are stale or fragmented, policy decisions drift away from actual risk.

Practical implication: Practitioners should treat identity telemetry and lifecycle hygiene as prerequisites for Zero Trust enforcement.

How machine identities expand the attack surface

Non-human identities include service accounts, API keys, tokens, certificates, and identities used by applications or agents. These identities often persist longer than the workload that created them, and they are frequently embedded in code, configs, CI/CD systems, or vaults with inconsistent rotation. That creates a broad, distributed trust surface that is difficult to see and even harder to revoke quickly. Because machine identities authenticate machine-to-machine, they can scale attacker access without interactive prompts, which is why they are attractive targets for persistence and lateral movement.

Practical implication: Teams need inventory, ownership, rotation, and offboarding controls for every machine identity, not just privileged human users.

Privilege controls that matter most for identity-first defence

Least privilege, secrets management, JIT access, and zero standing privilege form the privilege layer of an identity-first model. Each control reduces the amount of persistent access an attacker can reuse after compromise. Least privilege limits blast radius, secrets management reduces credential exposure, JIT reduces standing exposure windows, and ZSP removes durable admin rights that attackers often target. These controls are strongest when paired with access review and role or attribute-based policy so that access is both task-scoped and continuously validated.

Practical implication: Security architecture should tie these controls to measurable entitlement reduction, not just policy documentation.

Threat narrative

Attacker objective: The attacker aims to convert legitimate identity into durable access that bypasses perimeter defenses and sustains operations inside the environment.

1. Entry occurs when attackers obtain valid credentials or machine secrets and authenticate as trusted users or workloads.
2. Escalation follows when excessive privileges, standing admin rights, or weak lifecycle controls let the attacker expand access without triggering obvious alerts.
3. Impact is sustained by operating inside trusted identity flows, which supports stealthy exfiltration, ransomware, or fraud activity.

Breaches seen in the wild

• Sisense breach — unauthorized GitLab access led to exfiltration of access tokens, API keys and certificates.
• Dropbox Sign breach — compromised Dropbox Sign service account exposed API keys and OAuth tokens.

Read our 52 NHI Breaches Analysis report for a comprehensive view of breaches impacting Non-Human Identities including AI Agents.

NHI Mgmt Group analysis

Identity-first Zero Trust is now an NHI governance problem, not only an IAM program issue. The article is right to elevate identity as the decision point, but that decision point now includes service accounts, API keys, workload certificates, and agents. Once non-human identities outnumber humans, the governance model has to cover creation, use, rotation, and offboarding together. The practitioner conclusion is that Zero Trust cannot be credible if machine identities remain outside the same control plane as human access.

Ephemeral access controls are necessary, but they do not solve trust debt. JIT access and zero standing privilege reduce exposure windows, yet they still depend on accurate identity ownership, policy, and revocation. If stale secrets, orphaned accounts, or long-lived certificates remain in circulation, attackers can still exploit trusted paths. The operational lesson is to pair privilege reduction with lifecycle enforcement, or else the organization only moves the risk around.

Machine identity sprawl creates an identity blast radius that most enterprises do not measure well enough. The scale problem is not just volume, it is unmanaged overlap across apps, pipelines, and cloud services. When the same identity is reused in multiple systems, a single compromise can cascade faster than perimeter controls can react. Practitioners should measure blast radius as a governance metric, not just count identities.

Adaptive authentication is useful for humans, but it is not a full answer for autonomous or headless access. Many identity policies were built around interactive users, not non-interactive workloads that authenticate continuously. That mismatch leaves a governance gap when access is API-driven, automated, or delegated across services. The field needs policy, inventory, and revocation models that assume non-human identities will keep multiplying.

Zero Trust succeeds only when identity review becomes a continuous operational process. Annual certification and periodic audits are too slow for environments where identities can be created in code, propagated in pipelines, and reused instantly. The right control expectation is continuous visibility, fast revocation, and explicit ownership for every identity type. The practitioner implication is to move identity governance from audit support into active security operations.

From our research:

• 97% of NHIs carry excessive privileges, increasing unauthorised access and broadening the attack surface, according to the Ultimate Guide to NHIs.
• Only 20% have formal processes for offboarding and revoking API keys, and even fewer have procedures for rotating them, according to the Ultimate Guide to NHIs.
• For the broader pattern behind identity compromise, see 52 NHI Breaches Analysis for the recurring failure modes practitioners need to eliminate.

What this signals

Identity blast radius: the next governance debate is not whether identities should be protected, but how quickly they can be constrained once misuse starts. With 71% of NHIs not rotated within recommended time frames, the problem is no longer theoretical. That tells practitioners to invest in ownership, rotation, and revocation paths before adding more policy layers.

Zero Trust programmes that ignore machine identities will continue to miss the fastest-growing access paths in the enterprise. The control model has to extend beyond login events and into non-interactive authentication, because service accounts and automation can carry the same or greater privilege than employees. Teams should expect audit pressure to shift from human access reviews toward proof of lifecycle control for NHIs.

For practitioners

• Implement continuous inventory for all NHI credentials Track service accounts, API keys, tokens, certificates, and workload identities in one ownership model so you can see where each credential is used and who can revoke it.
• Reduce standing privilege in privileged workflows Replace persistent admin access with JIT approval paths, scoped elevation, and short-lived session controls for both humans and machine operators.
• Automate rotation and offboarding for machine identities Build rotation schedules and revocation workflows into pipelines so credentials are not left valid after application changes or team handoffs.
• Tie access reviews to actual identity lifecycle events Trigger certification when accounts change role, leave scope, or stop being used, instead of relying only on calendar-based review cycles.

Key takeaways

• Identity has become the practical control plane for Zero Trust because attackers increasingly use valid credentials rather than overt exploits.
• Machine identities expand the attack surface when ownership, privilege, and lifecycle controls are fragmented across teams and systems.
• Security leaders should pair privilege reduction with continuous lifecycle governance, or Zero Trust will remain incomplete for NHIs.

Key terms

• Non-Human Identity: A non-human identity is an access credential or account used by software, workloads, automation, or AI agents rather than people. It includes service accounts, API keys, tokens, certificates, and similar credentials that authenticate machine-to-machine activity and require ownership, lifecycle control, and revocation.
• Zero Standing Privilege: Zero standing privilege is a control model in which no identity keeps persistent elevated access by default. Privilege is granted only when needed and for a limited time, reducing the opportunity for misuse, credential theft, and lateral movement across environments.
• Just-in-Time Access: Just-in-time access provides temporary elevation for a defined task and then removes that access automatically or through workflow. In NHI governance, it reduces persistent privilege but still depends on accurate ownership, policy enforcement, and fast revocation when the task ends.
• Identity Blast Radius: Identity blast radius is the scope of damage an attacker can create after compromising a single identity. It reflects privilege breadth, reuse across systems, and how quickly access can be detected, constrained, and revoked before the compromise spreads further.

Deepen your knowledge

Identity-first Zero Trust and NHI governance are core topics in our NHI Foundation Level course, the industry's only accredited NHI security programme. If you are building a programme around machine identity visibility, privilege reduction, and lifecycle control, it is worth exploring.

This post draws on content published by CyberArk: How CISOs Can Use Identity to Advance Zero Trust. Read the original.