CloudHSM vs. KMS Comparison
As organizations increasingly rely on cryptography to protect sensitive information, selecting the right key management solution is critical. But what is the right tool? This page describes the differences between a Hardware Security Module (HSM) and a Key Management System (KMS).
Overview
Both HSMs and KMSes are used in cryptographic key management. However, they sit at different level in the stack and serve different use cases. Nevertheless, they also complement each other. Both can be deployed on-premise or in the cloud.
What is an HSM?
- What it is: A physical hardware device designed to securely generate, store, use, and manage cryptographic keys.
- Main function: Performs cryptographic operations (e.g., key generation, decryption, signing) in a tamper-resistant environment. Performs true random number generation. Has hardware acceleration for cryptographic operations.
- Security: Offers strong physical and logical protection. Certified under standards like FIPS 140-2 Level 3.
- Deployment: On-premise or in the cloud. The hardware is deployed similar to normal servers.
- Use cases:
- Root of trust for PKI
- Key storage for banking, government, or critical infrastructure
- Key storage for crypto currencies
- Hardware-based encryption for data protection
- Hardware to back a KMS
What is a KMS?
- What it is: A software application that manages the key lifecycle (generation, usage, rotation, deletion), usage policies, and access control.
- Main function: Simplifies and automates key usage and management across a large number of applications using keys. Simplifies access control and logging.
- Security: Typically uses HSMs under the hood to generate, store, and use the keys.
- Deployment: Either on-premise, or in the cloud. The software is deployed similar to normal applications.
- Use cases:
- Application-level encryption and signing
- Managing encryption keys for databases and object storage
- Enforcing key access policies and auditing
Comparison
| CloudHSM | Key Management System (KMS) | |
|---|---|---|
| Purpose | Key generation, storage, usage | Managing the key lifecycle, access control, audit trail |
| Protection | Physical, tamper-resistant hardware | Software-based, may be backed by an HSM |
| Examples |
|
|
When to choose CloudHSM vs. KMS?
Choose a CloudHSM if you need:
- Full ownership and low-level control over private keys.
- Compliance with strict regulations (e.g., financial institutions, government).
- High performance for cryptographic operations.
- Integration with on-premise or multi-cloud workloads.
- An HSM to back a KMS with hardware-level performance and security.
Choose a KMS if you need:
- Automated key lifecycle management (such as automatic key rotation).
- Detailed logging and auditing.
- Powerful access control policies.
- Seamless integration with cloud-native applications.