In the modern enterprise, identity has become the new security perimeter. But when we talk about identity, we're really talking about two fundamentally different types: human identities and machine identities. Understanding both is essential for comprehensive security.
The Two Identity Types
Human Identities
- Employees, contractors, partners
- Managed through HR processes
- Authenticate via passwords, MFA, biometrics
- Subject to awareness training
- Predictable lifecycle (hire to terminate)
- Visible in directory services
Machine Identities
- APIs, services, containers, certificates
- Created by developers and automation
- Authenticate via keys, tokens, certificates
- Often hardcoded or stored insecurely
- Unpredictable lifecycle
- Frequently invisible or undocumented
Why Machine Identities Are Overlooked
Organizations have spent decades building processes around human identity management. HR handles onboarding, IT provisions accounts, and security enforces access policies. But machine identities emerged organically, created by developers who needed applications to communicate.
Common blind spots include:
- Service accounts: Created for applications but rarely reviewed or rotated
- API keys: Often shared, hardcoded, and forgotten
- Certificates: Expire unexpectedly, causing outages and security gaps
- Secrets in code: Credentials committed to repositories
- Cloud IAM roles: Over-permissioned for convenience
"Attackers don't distinguish between human and machine identities. They'll use whatever access path is easiest. Often, that's the service account with admin privileges that no one remembers creating."
The Unified Identity Challenge
Modern identity security requires treating both human and machine identities with equal rigor. This means applying the same principles:
Principle of Least Privilege
Whether human or machine, every identity should have only the access required to perform its function—nothing more. This applies to service accounts just as much as user accounts.
Lifecycle Management
Both identity types need clear processes for creation, modification, and termination. Machine identities should have defined owners and expiration dates.
Continuous Monitoring
Behavioral analytics should track both human and machine activities. Anomalous API calls are just as concerning as unusual user logins.
Regular Attestation
Access reviews shouldn't be limited to human identities. Service account permissions need periodic validation too.
Building a Unified Strategy
- Inventory everything: Discover all machine identities in your environment
- Assign ownership: Every machine identity needs a responsible human
- Implement secrets management: Centralize and secure credential storage
- Automate rotation: Credentials should rotate regularly without manual intervention
- Monitor continuously: Detect unusual patterns in both human and machine behavior
- Integrate with IAM: Bring machine identities into your identity governance program