An API key is a unique string of characters used to authenticate and identify an application or user when interacting with an API. It acts as a simple form of credential that verifies who or what is making a request, without requiring a full authentication protocol.
How API Keys Work
When an application wants to access an API, it includes its API key in the request header or URL. The API validates this key against its records to determine whether the request is allowed.
Typically:
- The API provider issues a unique key to each developer or service.
- That key is embedded in API calls made by the application.
- The API server verifies the key before processing the request.
While straightforward, API keys do not include built-in encryption, expiration, or fine-grained authorization. They simply identify the caller, not what they’re allowed to do. This makes them lightweight but also inherently insecure when used as the sole access mechanism.
Modern systems often replace or supplement API keys with OAuth tokens, workload identities, or mutual TLS certificates, which provide stronger authentication and authorization guarantees.
Why API Keys Matter
API keys are the lowest-friction way to enable programmatic access between services, mobile apps, and external integrations.
For developers, they offer:
- Fast onboarding for third-party integrations.
- Minimal setup for internal APIs.
- Simple tracking of usage and quotas.
In practice, though, API keys are a legacy control in today’s security environment. As infrastructures grow more distributed, spanning cloud services, microservices, and AI workloads, API keys often become an unmanaged sprawl of long-lived credentials, increasing the risk of data exposure and unauthorized access.
For enterprises adopting Zero Trust and workload identity principles, phasing out static API keys is a crucial modernization step.
Common Challenges
Identity-based Challenge
- Credential Sprawl: API keys are often issued, copied, and reused across services without centralized visibility. This makes it impossible to trace which workload owns which key, or to revoke them safely.
Non-identity Challenges
- Security Exposure: Keys stored in code repositories, logs, or configuration files can be easily leaked, leading to unauthorized access.
- Limited Authorization: API keys can identify the caller but cannot enforce fine-grained permissions like “read-only” or “admin” scopes.
- Key Lifecycle Management: Rotating or revoking keys across distributed systems requires manual coordination.
- Audit Gaps: Most APIs only log key usage, not contextual information (such as which service or workload was behind the request), limiting incident investigation.
How Aembit Helps
Aembit replaces traditional API key–based access with identity-driven authentication that verifies and governs each workload’s existing, attested identity. Instead of static credentials, Aembit brokers secure, short-lived access between workloads and APIs under centralized policy control.
With Aembit:
- Workloads connect without sharing or storing secrets.
- Access is enforced through dynamic, policy-based authorization rather than static keys.
- Credentials are issued just-in-time and expire automatically, removing the need for manual key rotation.
- Security teams gain unified visibility and auditability across all machine-to-machine API calls.
If an API key must still be used, Aembit can securely vault, fetch, and inject it at runtime, so the key never appears in code or configuration files. This allows organizations to modernize securely, even when legacy integrations still depend on static credentials.
In short, Aembit helps organizations retire API-key sprawl and move to secretless, identity-aware access aligned with Zero Trust principles.
Related Reading
Related Terms:
OAuth Token, Service Account, Secret Management, Zero Trust
FAQ
You Have Questions?
We Have Answers.
What is workload identity and access management?
Workload identity and access management (WIAM) is a security approach that assigns unique identities to workloads and manages their access to resources based on defined policies. Unlike traditional methods that rely on static credentials, WIAM uses a variety of credential types including dynamic, short-lived credentials and real-time identity verification to ensure secure, policy-driven access control. The concept of attestation means that the identity of the workload is cryptographically verified using a 3rd party attestor. Conditional access policies enable Zero Trust controls to be enforced even when the end service doesn’t directly support them.
Most IAM vendors are focused on users, while Workload IAM are for non-user identities, sometimes called non-human or machine identities.
What is a workload?
A workload refers to any non-human entity—such as AI agents, applications, services, scripts, or containers—that is accessing a service or data. A client workload (the source) will be accessing a server workload (the destination). Your application running in your Kubernetes environment is an example of a client workload. The client workloads often need to communicate with server workloads inside and outside of your network, necessitating secure authentication and authorization mechanisms. Using Stripe for payment processing and AWS S3 buckets to store and access data are examples of server workloads.
I carefully manage secrets already. Isn't that good enough?
Traditional approaches often involve hardcoded credentials, shared secrets, or static API keys, which pose significant security risks. These methods are susceptible to breaches, lack scalability, and are challenging to maintain and audit. Aembit addresses these issues by eliminating the need for stored secrets, providing dynamic credential injection, and offering centralized policy management for improved security and compliance. Aembit’s secretless approach also means a better developer experience. Developers no longer need to store, access, and code for authentication.
Can you do zero trust for workloads?
Yes. Aembit applies zero trust principles to workloads by verifying the identity of each workload when it requests access in real-time, regardless of the workload’s location. This involves cryptographic identity verification, policy-based access controls, and the use of short-lived credentials, ensuring that only authorized workloads can access specific resources. Aembit also applies MFA for workloads, just like you do for users.
When your users are accessing your data and services, you can ensure that the system is secured using corporate issued software, verify their geo-location, and that they are connecting during business hours. You can now do the same for your workloads.