AWS Key Management Service vs OpenKCM (Open Key Chain Manager)
AWS Key Management Service
aws.amazon.com
OpenKCM (Open Key Chain Manager)
openkcm.ioSide by side
| Figure | AWS Key Management Service | OpenKCM (Open Key Chain Manager) |
|---|---|---|
| Price from | $1/mo | — |
| Free plan | — | — |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | — |
| Linux | — | Yes |
| API | Yes | Yes |
| Self-hosted | — | Yes |
| Plans published | 1 | 0 |
| Spec score · Key Management Software | 8.0 (#2) | 7.1 (#11) |
| Spec score · Encryption Key Management Software | 8.0 (#4) | 7.3 (#10) |
| Cryptographic operations | KMS supports symmetric encryption, asymmetric signing or encryption key pairs, and generation and verification of HMACs. | The Krypton execution plane wraps and unwraps keys using keys temporarily loaded into secure memory. |
| External key stores | With an external key store, keys are generated and stored in an external key manager that the customer owns and manages, and key material stays in that HSM. | The trust model names AWS, Azure, and GCP key services and on-premise HSMs as locations for customer root keys. |
| Integrations | KMS integrates with AWS services including Amazon S3, Amazon EBS, Amazon RDS, Amazon DynamoDB, AWS Lambda, and AWS CloudTrail. | The trust model names AWS, Azure, and GCP external KMS services and on-premise Thales or Entrust HSMs as locations for customer root keys. |
| Key management | KMS provides centralized control over key lifecycles and permissions, including separate control over who manages keys and who uses them. | It supports key hierarchies, importing customer keys through BYOK, and keeping master keys in the customer’s infrastructure through HYOK. |
| Purpose | AWS KMS creates and controls cryptographic keys used to encrypt data and digitally sign it. | OpenKCM is an open-source key management service for managing cryptographic keys across services and regions. |
Plans
In their own words
AWS Key Management Service
AWS Key Management Service creates and controls cryptographic keys for data encryption and digital signatures. It centralizes key lifecycles and permissions, including separate control over administrators and key users. KMS supports symmetric encryption, asymmetric signing or encryption pairs, and HMAC generation and verification. The AWS Encryption SDK can use KMS as a key provider for local application encryption and decryption. Integrations include Amazon S3, EBS, RDS, DynamoDB, Lambda, and CloudTrail. With CloudTrail enabled, requests can record the user, time, API action, and key. AWS says hardware security modules validated to FIPS 140-3 Security Level 3 protect key material and operations, with plaintext keys kept only in volatile HSM memory. Multi-Region keys support cross-Region workflows; external key stores keep material in a customer-managed external manager. KMS scales with demand but has default key and request limits. The listed plan is $1 a month per KMS key, prorated hourly.
OpenKCM (Open Key Chain Manager)
OpenKCM (Open Key Chain Manager) is a free, open-source key management service for governing encryption keys and protecting data at rest. It supports BYOK key import and HYOK, which keeps master keys in a customer’s infrastructure. Its recursive L1–L4 hierarchy makes data keys dependent on higher-level keys. Governance and policy control are handled by CMK, while Krypton performs cryptographic execution; applications request key operations through the KMIP API.
The Gateway is designed to run near applications, such as in Kubernetes or a cloud VPC, and the same software can operate across AWS, Azure and on-premise environments. Customer root keys can remain in AWS, Azure or GCP key services, or on-premise HSMs, while OpenKCM holds a reference to the L1 key. A kill switch can halt downstream key use by removing that reference or revoking the root key. CMK connects to a corporate identity provider and sends audit logs to SIEM systems. The project’s CMK and Krypton components are actively being developed; encryption and decryption operations are in progress, while audit export, high availability and disaster recovery are planned for 2027.