Best practices for KMS

Here are some guidelines to maximize the security and efficiency of using KMS:

• Access control: Adhere to the principle of least privilege. Limit access to keys to only those who need it, and use policies to enforce these restrictions.
• Audit logging: Enable CloudTrail to log all API requests made on your KMS keys. This is crucial for compliance and for investigating any security incidents.
• Key rotation: KMS supports automatic key rotation for CMKs, but it is also advisable to periodically review and manually rotate keys when necessary. This ensures that your encryption remains robust against potential vulnerabilities.
• Multi-region replication: For applications that are globally distributed, consider replicating your keys in multiple regions to reduce latency and improve availability.
• Use aliases and tagging: Rather than directly referencing keys by their key ID, employ aliases and tags for easier key management. Aliases simplify the process of switching between keys without altering your application code, while tags facilitate better organization and tracking of your keys and allow for ABAC.
• Encryption context: Use the encryption context for additional authenticated data to ensure that the ciphertext and the encryption context are not changed.

With these practices in place, organizations can ensure efficient and secure key management using KMS. Now, let’s focus our attention on the more advanced AWS alternative that organizations can utilize to manage their keys: AWS CloudHSM.

CloudHSM integration and use cases

CloudHSM is an HSM that’s designed for generating and using your cryptographic keys within AWS. While KMS offers a multi-tenant, managed service for cryptographic operations, CloudHSM provides a dedicated physical device in a single-tenant environment. This ensures a higher level of isolation for your most sensitive cryptographic operations and compliance with stringent regulatory requirements as it is FIPS 140-2 Level 3 validated. CloudHSM is particularly valuable in scenarios where specific use cases necessitate this level of isolation and control beyond the capabilities of the standard KMS environment.