1---
2layout: "docs"
3page_title: "Seals - Configuration"
4sidebar_title: "<code>seal</code>"
5sidebar_current: "docs-configuration-seal"
6description: |-
7  The seal stanza configures the seal type to use for additional data protection.
8---
9
10# `seal` Stanza
11
12The `seal` stanza configures the seal type to use for additional data
13protection, such as using HSM or Cloud KMS solutions to encrypt and decrypt the
14master key. This stanza is optional, and in the case of the master key, Vault
15will use the Shamir algorithm to cryptographically split the master key if this
16is not configured.
17
18As of Vault 0.9.0, the seal can also be used for [seal wrapping][sealwrap] to
19add an extra layer of protection and satisfy compliance and regulatory requirements.
20This feature is only available in Vault Enterprise.
21
22For more examples, please choose a specific auto unsealing technology from the
23sidebar.
24
25## Configuration
26
27Seal configuration can be done through the Vault configuration file using the
28`seal` stanza:
29
30```hcl
31seal [NAME] {
32  # ...
33}
34```
35
36For example:
37
38```hcl
39seal "pkcs11" {
40  # ...
41}
42```
43
44For configuration options which also read an environment variable, the
45environment variable will take precedence over values in the configuration file.
46
47[sealwrap]: /docs/enterprise/sealwrap/index.html
48