Security For Windows Nodes [page]deterministic
This page describes security considerations and best practices specific to the Windows operating system.
## Protection for Secret data on nodes
On Windows, data from Secrets are written out in clear text onto the node's local storage (as compared to using tmpfs / in-memory filesystems on Linux). As a cluster operator, you should take both of the following additional measures:
1. Use file ACLs to secure the Secrets' file location. 1. Apply volume-level encryption using [BitLocker](https://docs.microsoft.com/windows/security/information-protection/bitlocker/bitlocker-how-to-deploy-on-windows-server).
## Container users
[RunAsUsername](/docs/tasks/configure-pod-container/configure-runasusername) can be specified for Windows Pods or containers to execute the container processes as specific user. This is roughly equivalent to [RunAsUser](/docs/concepts/security/pod-security-policy/#users-and-groups).
Windows containers offer two default user accounts, ContainerUser and ContainerAdministrator. The differences between these two user accounts are covered in [When to use ContainerAdmin and ContainerUser user accounts](https://docs.microsoft.com/virtualization/windowscontainers/manage-containers/container-security#when-to-use-containeradmin-and-containeruser-user-accounts) within Microsoft's _Secure Windows containers_ documentation.
Local users can be added to container images during the container build process.
> Note: * [Nano Server](https://hub.docker.com/_/microsoft-windows-nanoserver) based images run as `ContainerUser` by default * [Server Core](https://hub.docker.com/_/microsoft-windows-servercore) based images run as `ContainerAdministrator` by default
Windows containers can also run as Active Directory identities by utilizing [Group Managed Service Accounts](/docs/tasks/configure-pod-container/configure-gmsa/)
## Pod-level security isolation
Linux-specific pod security context mechanisms (such as SELinux, AppArmor, Seccomp, or custom POSIX capabilities) are not supported on Windows nodes.
Privileged containers are [not supported](/docs/concepts/windows/intro/#compatibility-v1-pod-spec-containers-securitycontext) on Windows. Instead [HostProcess containers](/docs/tasks/configure-pod-container/create-hostprocess-pod) can be used on Windows to perform many of the tasks performed by privileged containers on Linux.