Key takeaways
A non-human identity (NHI) is any digital identity assigned to a machine, application, or automated process rather than a person. Service accounts, API keys, OAuth tokens, and cloud workload identities are all NHIs.
NHIs vastly outnumber human users in the average enterprise, and most were created quickly, given broad permissions, and never reviewed again.
A compromised NHI grants an attacker persistent, automated access to whatever the identity can access, with no human to notice that something is wrong.
The most common vulnerabilities are overprivileged accounts, credential leakage, and identity sprawl. Most identity tools were built for people and were never designed to catch these problems at machine scale.
Securing NHIs requires discovering what exists, scoping permissions to what each identity actually needs, and continuously monitoring behavior.
What is a non-human identity?
A non-human identity is a digital identity assigned to a machine, application, service, or automated process rather than a person. Like a human user, an NHI has credentials and permissions that define what it can access. Unlike a human user, it often has no one to watch over it.
Where a human identity includes a name, a job role, and a password, a non-human identity includes things like an API key, a service account name, or a machine certificate. These credentials let machines authenticate to other machines and automated workflows run without human intervention.
In the average enterprise, NHIs outnumber human users by more than 45 to 1, and in cloud-native and DevOps environments, that ratio climbs to 144 to 1 or higher. Most were created quickly, given broad permissions, and never reviewed again. Traditional identity and access management tools were built for people, not machines. Applying zero trust principles to NHIs is how organizations can close that gap.
What do non-human identities do?
Non-human identities connect systems to each other. They authenticate applications to databases, automate workflows between platforms, and keep infrastructure running without human intervention. They come in several forms, each serving a different purpose and carrying different security risks.
What are the types of non-human identities?
Non-human identities come in several forms. Each serves a different automation or integration purpose, carries different credentials, and introduces different security risks. A company with 500 employees might manage thousands of NHIs across its environment.
API keys and secrets
An API key is an authentication credential that an application uses to access an external service. Secrets are sensitive configuration values like passwords, tokens, and encryption keys that applications need to function. A payment processing application might use an API key to connect to a payment gateway. A backend service might store database connection strings as secrets in a configuration file or a dedicated vault.
API keys and secrets present a common leak risk among NHI credential types. They are often hardcoded into application source code or committed to version control repositories, where they can be discovered by attackers.
Service accounts and bots
A service account is a special account created for an application or service rather than an individual user. A bot is an automated program that performs repetitive tasks. A cloud service account might back up databases every night while a Slack bot might automate employee reminders. A monitoring service account might check system health every 60 seconds and write the results to a dashboard.
Cloud platforms implement service accounts differently. AWS uses IAM roles. Azure uses managed identities. Google Cloud uses service accounts with key files. Each operates under a different permission model, which makes consistent governance across platforms difficult.
Cloud workloads and container identities
These are identities assigned to virtualized computing resources, including virtual machines, containers, serverless functions, and Kubernetes pods. A Docker container accessing a cloud database needs an identity. A Kubernetes pod retrieving configuration from a key vault needs an identity. A serverless function writing to a message queue needs an identity.
Containerization and cloud-native architectures have increased the number of these identities dramatically. A single microservices application might run dozens of containers—each with its own credentials—and those containers might be created and destroyed hundreds of times per day.
Why does non-human identity matter for security?
Non-human identities matter because they combine access with minimal oversight. Most NHIs were created for convenience and speed and given the permissions they needed to work (often more than they need) and then left alone. They do not forget or change their passwords. They do not enroll in multi-factor authentication (MFA). They do not report suspicious activity on their accounts. They just keep running.
This makes them high-value targets. A compromised NHI gives an attacker authenticated, automated access to whatever the identity can reach. For attackers, this means persistent, hard-to-spot, and powerful access. After all, NHI credentials are rarely rotated, activity is rarely monitored, and NHIs frequently hold elevated privileges.
The specific risks include:
Credential theft. Stolen API keys or service account credentials give attackers persistent access that does not depend on a human being logged in.
Privilege escalation. Compromised NHIs with excessive permissions let attackers reach deeper into systems than the initial entry point would typically allow.
Data exfiltration. NHIs with automated access to databases and storage systems can move data at machine speed, far faster than a human user copying files.
Supply chain attacks. A compromised CI/CD pipeline identity can inject malicious code into production software that reaches customers. AI agents, a fast-growing category of non-human identity with access to tools, APIs, and production systems, amplify this risk further.
What are the biggest challenges in non-human identity management?
The security risks above are made worse by four access management challenges that affect nearly every organization.
Overprivileged accounts
NHIs are frequently granted more permissions than they need. Developers and administrators assign broad access to avoid troubleshooting permission errors during deployment. But, what if a service account that needs read access to one database ends up with admin rights across the entire environment? If that account is compromised, the attacker inherits every permission it holds.
Identity sprawl
Cloud adoption, DevOps velocity, and ephemeral infrastructure create and destroy NHIs dynamically, often without centralized tracking. Organizations lose visibility into what non-human identities exist, where they are used, and what permissions they hold. Orphaned credentials from decommissioned applications remain active long after they are needed.
Credential leakage
NHI credentials are frequently exposed through insecure storage or accidental publication. Common scenarios include hardcoded credentials in source code, API keys committed to public GitHub repositories, secrets stored in unencrypted configuration files, and credentials shared through messaging platforms like Slack.
In 2025 alone, more than 28 million hardcoded secrets were detected in public GitHub commits. Unlike a compromised human password, a leaked NHI credential often goes unnoticed for months or years because there is no human owner to report suspicious activity on the account.
Lack of continuous monitoring
Traditional identity and access management tools were designed for human users. They track logins, enforce password policies, and require MFA at the front door.
NHIs operate at machine scale and speed, and most IAM tools do not apply the same behavioral monitoring or anomaly detection to them. As a result, many security teams cannot answer basic questions such as which service account accessed what data?, When did this API key last authenticate?, and Has this bot's access pattern changed?
Identity threat detection and response (ITDR) applies the behavioral monitoring and anomaly detection that traditional IAM tools were never built to provide for machine identities.
The scope of non-human identity risk
These numbers show why non-human identity security has become a priority for security teams across industries.
1. Rubrik Zero Labs 2025, via The Hacker News 2026; 2. Cloud Security Alliance, State of SaaS Security 2025-2026; 3. Git Guardian State of Secrets Sprawl 2026, via Help Net Security.
What are the best practices for securing non-human identities?
The standard identity security playbook covers four phases: discover, assess, remediate, and monitor. It applies to NHIs, but the execution is different. Human identities have owners who respond to MFA prompts, reset their own passwords, and notice when something is wrong with their account. Non-human identities have none of that.
1. Assign an owner to every non-human identity
This is the single most important step and the one most organizations skip.
Human accounts have obvious owners. NHIs often do not. A developer creates a service account during a sprint, the sprint ends, the developer moves to another project, and the account keeps running with no one responsible for it. When a security team discovers 3,000 unowned service accounts, they have no way to determine which ones are still needed and which ones should be decommissioned.
Identity security posture management (ISPM) platforms automate this discovery, continuously scanning for unowned, overprivileged, and orphaned NHIs so security teams can work from a current inventory.
Every NHI should have a named human owner accountable for its permissions, credential rotation, and eventual decommissioning. Automate ownership assignment during provisioning, so it is never skipped.
2. Move secrets out of code and into vaults
Hardcoded credentials in source code are the most common NHI compromise vector. They end up in version control history, get copied into collaboration tools, and persist long after the code is refactored.
Centralized secret management systems like HashiCorp Vault, AWS Secrets Manager, or Azure Key Vault store credentials separately from application code and control access programmatically. Pair vault adoption with repository scanning tools—software that automatically checks source code and version control history for exposed credentials—to catch hardcoded secrets before they reach production.
3. Replace static credentials with short-lived tokens
A static API key that never expires is a permanent door into whatever system it accesses. Short-lived tokens and temporary credentials reduce the window of exposure.
Cloud platforms support this natively: AWS Security Token Service issues temporary credentials, Azure managed identities eliminate stored secrets entirely, and Google Cloud workload identity federation lets services authenticate without key files.
Where static keys are unavoidable, enforce automated rotation on a schedule tied to risk:
High-privilege: 30 days
Medium-privilege: 60 days
Low-privilege: 90 days
4. Scope permissions to exactly what the identity needs, and nothing else
Audit NHI actual usage against granted permissions. If an identity has write access but only ever reads, downgrade it. If it accesses one database but has credentials for ten, revoke the other nine. Use just-in-time access for elevated privileges by granting them for the duration of the task and revoking them automatically when it ends.
5. Automate the full credential lifecycle
When an employee joins, changes roles, or leaves an organization, HR-driven processes handle the transitions—such as onboarding, role changes, and offboarding. NHIs should get the same treatment. That means creating credentials through documented, repeatable workflows rather than ad hoc manual creation. This requires setting automatic expiration dates for project-specific or temporary identities and tying decommissioning to application lifecycle events so that when a service is retired, its credentials are revoked automatically.
The goal is to eliminate the category of orphaned credentials that remain active indefinitely because no process exists to remove them.
6. Monitor NHI behavior separately from human activity
NHIs and human users produce fundamentally different telemetry. A person logs in once or twice a day. A service account might authenticate thousands of times per hour. Applying human behavioral baselines to machine activity produces nothing but noise. Build separate baselines for each NHI such as typical access times, resources accessed, API call volumes, and source locations. A service account that has queried the same database on the same schedule for six months and suddenly starts writing to an external API at 3:00 AM is behaving anomalously. Feed NHI activity into your SIEM for correlation but keep the detection logic tuned to machine patterns and scale.
Recommended audit frequencies by NHI risk level:
Risk level | Access review and credential rotation | Inactivity threshold |
|---|---|---|
High (admin privileges, sensitive data) | Monthly review, 30-day rotation | 30 days |
Medium (production access, limited scope) | Quarterly review, 60-day rotation | 60 days |
Low (read-only, non-production) | Semi-annual review, 90-day rotation | 90 days |
Strengthening NHI security with Duo
Securing non-human identities requires an approach that protects both human and machine identities within a unified framework. Cisco Duo supports this approach across several layers:
Phishing-resistant MFA provides strong identity verification that prevents credential-based attacks at the authentication layer, protecting the human accounts that create, manage, and govern NHIs.
Adaptive access policies adjust authentication requirements based on real-time risk context, including device health, location, and behavior for all identity types.
Identity intelligence provides visibility into authentication patterns, failed attempts, and anomalies across the systems Duo protects.
Duo connects to existing identity providers, secret management tools, cloud IAM platforms, and other security infrastructure and tools through standard connectors without requiring changes to existing infrastructure.
Duo's approach prioritizes protection without sacrificing the operational efficiency that makes automation valuable. Strong authentication at the human layer prevents attackers from compromising the accounts that control NHI provisioning and governance. Adaptive policies ensure that access decisions account for risk context across both identity types.
Ready to strengthen your organization's human and non-human identity security? Start a Duo free trial today.