AWS Secrets Manager vs. HashiCorp Vault

Secret Management as a Cloud Function or as a Standalone Security Architecture

Secrets are not a fringe topic. Credentials, API keys, tokens, and certificates define how systems are allowed to communicate—and where security boundaries actually lie. AWS Secrets Manager and HashiCorp Vault address this issue from two fundamentally different perspectives.

The difference is not in the ability to store secrets encrypted. It lies in the question of whether secret management is part of a cloud function or represents a standalone security architecture. This decision directly impacts portability, governance, and long-term control.

AWS Secrets Manager: Secret Handling as a Cloud Service

AWS Secrets Manager is AWS’s managed service for storing and utilizing sensitive information such as credentials, API keys, or tokens. Secrets are stored encrypted, versioned, and can be automatically rotated—especially for AWS-native services like RDS.

The integration into IAM, CloudTrail, Lambda, and other AWS services is deep. Access controls follow the IAM model, audit logs are centrally available, and the operational effort is low. There are no servers, no own high availability logic, no scaling questions. Secret management is consumed—similar to other AWS security services.

For clearly AWS-centered architectures, this is consistent and efficient. However, this alignment is structural.

Cloud-Specific Rather Than Universal

AWS Secrets Manager is not a universal secret layer. It is a cloud-specific service. Access is via AWS APIs, permissions follow the IAM logic, and rotation is primarily intended for AWS services.

In Kubernetes, hybrid, or multi-cloud environments, Secrets Manager becomes an external dependency point. Applications must know cloud-specific access paths or be connected via additional components. Secret usage is technically possible but lies outside the actual platform logic.

Secrets here are subordinated to the cloud—not to the application or the security architecture.

HashiCorp Vault: Secrets as Security Infrastructure

HashiCorp Vault takes a fundamentally different approach. Vault is an open-source solution for the central management of secrets, certificates, and cryptographic material. It is not merely a storage solution but an active component of the security architecture.

Vault supports dynamic secrets, time-limited credentials, finely granular policies, and comprehensive audit logs. The service can be operated as a standalone component—on-premises, in Kubernetes, or in cloud environments—and integrates with applications and platforms via open interfaces.

Secrets are not statically distributed but generated on demand and automatically revoked.

Architectural Role: Storage vs. Control Instance

The architectural difference lies in the role of secrets. AWS Secrets Manager stores and distributes them. Vault controls their lifecycle.

Access follows clearly defined policies, independent of the cloud provider. [Kubernetes] authentication, service identities, mTLS scenarios, and short-lived credentials are integral parts of the model. Applications do not receive “a secret” but time- and context-limited access.

Thus, secret management becomes an active security mechanism—not a configuration issue.

Deliberate Design Instead of Managed Shortcut

This control requires deliberate design. Vault is not a managed shortcut. High availability, storage backend, monitoring, backup strategies, and lifecycle management must be actively implemented. This significantly increases the initial effort.

In return, a consistent secret layer is created across all environments. Auditability is central, policies are uniform, and the separation between application, platform, and infrastructure remains intact. Security decisions are not implicitly made by a cloud provider but explicitly by one’s own architecture.

Relevance for Kubernetes and Regulated Environments

In Kubernetes-centered platforms or environments with regulatory requirements, the assessment shifts significantly. AWS Secrets Manager simplifies secret handling within AWS. Vault establishes a standalone security component that unifies secrets, identities, and access control independently of individual platforms.

Especially with requirements from NIS-2, data protection, auditability, or tenant separation, this independence is crucial. Vault allows for consistent implementation of security models—even when infrastructure or providers change.

Condensed Comparison

When Each Approach Makes Sense

AWS Secrets Manager is suitable for:

• Purely AWS-centered architectures
• Tight integration with AWS services
• Low requirements for platform independence
• Focus on minimal operational effort

HashiCorp Vault is suitable for:

• [Kubernetes]- and platform-centered architectures
• Regulated or security-critical environments
• Dynamic credentials and zero-trust approaches
• Organizations with a demand for long-term sovereignty

Conclusion

Secrets are not configuration details. They define how far security is outsourced to a provider.

AWS Secrets Manager subordinates secret management to the cloud. HashiCorp Vault establishes it as a standalone security architecture.

The difference is not functional but strategic. Those who view secrets as a cloud function accept dependency. Those who see them as infrastructure retain control—even when platforms, providers, or regulatory frameworks change.