--- layout: docs page_title: Vault HSM support overview description: >- Review how HSM support in Vault works with external root key storage and automatic unsealing. --- > [!IMPORTANT] > **Documentation Update:** Product documentation, which were located in this repository under `/website`, are now located in [`hashicorp/web-unified-docs`](https://github.com/hashicorp/web-unified-docs), colocated with all other product documentation. Contributions to this content should be done in the `web-unified-docs` repo, and not this one. Changes made to `/website` content in this repo will not be reflected on the developer.hashicorp.com website. # Vault HSM support overview @include 'alerts/enterprise-only.mdx' - Root key Wrapping: Vault protects its root key by transiting it through the HSM for encryption rather than splitting into key shares - Automatic Unsealing: Vault stores its HSM-wrapped root key in storage, allowing for automatic unsealing - [Seal Wrapping](/vault/docs/enterprise/sealwrap) to provide FIPS KeyStorage-conforming functionality for Critical Security Parameters - [Entropy Augmentation](/vault/docs/enterprise/entropy-augmentation) to allow Vault to sample entropy from an external cryptographic module. HSM support is available for devices that support PKCS#11 version 2.20+ interfaces and provide integration libraries, and is currently available for linux/amd64 platforms only. It has successfully been tested against many different vendor HSMs; HSMs that provide only subsets of the full PKCS#11 specification can usually be supported but it depends on available cryptographic mechanisms. Please note however that configuration details, flags, and supported features within PKCS#11 vary depending on HSM model and configuration. Consult your HSM's documentation for more details. Some parts of Vault work differently when using an HSM. Please see the [Behavioral Changes](/vault/docs/enterprise/hsm/behavior) page for important information on these differences. The [Configuration](/vault/docs/configuration/seal/pkcs11) page contains configuration information. The [Security](/vault/docs/enterprise/hsm/security) page contains information about deploying Vault's HSM support in a secure fashion. Finally, the [HSM partners](/vault/docs/partners/hsm) page contains information about HashiCorp partner products that have been verified to work with Vault for Auto Unsealing / HSM Support and External Key Management.