Key Points
- Non-human identities (NHIs) are digital credentials assigned to non-human entities like AI agents, workloads, and IoT devices.
- The number of non-human identities is exploding, often outnumbering humans by a ratio of 50 to 1 in modern enterprises.
- Traditional authentication methods for NHIs like API keys and OAuth tokens are vulnerable to theft and lateral movement because they act as bearer tokens.
- PKI-based certificates are the gold standard for securing non-human identities, providing phishing-resistant, cryptographic proof of identity.
The modern internet is full of programs, bots, and accounts that aren’t associated with any human — these are non-human identities (NHIs). In most cases NHIs are simply doing a job, from authenticating applications to moving data around. But their prevalence, and their lack of oversight, make NHIs a potential vector for cyberattacks. Authenticating and monitoring NHIs on your network is a priority to ensure intruders stay out.
What Is a Non-Human Identity?
A non-human identity (NHI) is a digital identity assigned to an entity like a service account, API key, container, or serverless function rather than a person. These accounts belong to machines and applications that perform their functions automatically, often with little to no oversight.
In the past, network security focused primarily on human users. However, as organizations transition to the cloud, the vast majority of network “users” are now non-human entities.Because these accounts often operate 24/7 and can have “super user” permissions to access sensitive databases or perform financial transactions, they represent a significant security risk if not managed correctly.
The Evolution of NHIs: From IoT to AI Agents
The types and functions of non-human identities has matured as technology has evolved. We generally see three distinct forms of NHIs today:
- IoT Identities: These were the earliest NHIs, used for authenticating physical devices like sensors or diagnostic tools in healthcare.
- Machine Identities: This expanded the scope to include cloud infrastructure, DevOps containers, and application-to-application communication.
- AI Agents: The newest and most complex form of NHI. These agents use LLMs to interact with systems and can perform independent actions on behalf of a user.
How Non-Human Identities Authenticate Today
NHIs use various mechanisms to prove their identity to a network or another application.
| Authentication Method | Security Level | Risk Factor |
| API Keys | Low | No expiration; easily stolen from config files. |
| OAuth Tokens | Medium | Susceptible to hijacking in non-encrypted tunnels. |
| Digital Certificates | High | Phishing-resistant; hardware-backed private keys. |
The Bearer Token Problem
Many organizations currently rely on API keys and OAuth tokens for their non-human identities because they are easy to implement. That approach is a security risk because these methods are fundamentally “bearer tokens.”
If an attacker intercepts an API key, they effectively “bear” that identity and can move laterally through the network to access emails, databases, and financial systems. Because many NHIs lack a context-aware validity period, a stolen token can provide a hacker with unlimited access for days or even months. More intelligent methods can revoke access based on signals like suspicious behavior to clamp down on stolen credentials.
Why PKI Is the Gold Standard for NHIs
To secure non-human identities, the SecureW2 JoinNow platform enables the transition to Public Key Infrastructure (PKI). Unlike bearer tokens, PKI-based certificates use asymmetric cryptography involving both public and private keys.
Public keys are used for encryption, while private keys allow for decryption. While the public key is available to anyone, the private key associated with the NHI never leaves the source device or workload, meaning it cannot be stolen in transit. This approach creates a “phishing-resistant” environment that is fully aligned with zero-trust principles.
Scaling NHI Security with SPIFFE and Spire
Managing NHIs at “machine speed” requires automation. Universal standards like SPIFFE (Secure Production Identity Framework for Everyone) allow organizations to issue uniquely verifiable IDs to workloads on demand. SPIFFE specifies how organizations issue and manage identities for different software systems across different types of environments.
Using an implementation like Spire (SPIFFE Runtime Environment), the network carries out the process of attestation on both workloads and nodes to validate identity before issuing a short-lived certificate. This ensures that every AI agent or bot has a temporary, cryptographic identity with a complete audit trail — fulfilling the strict governance requirements of modern regulations like the EU AI Act.
Network security solutions from SecureW2 like the JoinNow Platform enable automated, frictionless authentication even for large, heterogenous networks that include both humans and non-human users. Ready to strengthen your network security with a passwordless solution? Schedule a SecureW2 demo today.
