ECryptfs

eCryptfs is Article description::an in-kernel file encryption suite.

Emerge
Install :

Note: The USE flags above are not up to date. must be compiled with the  USE flag in order to use the auto-mount capabilities of PAM as described below.

/etc/pam.d
See the below diff for the file.

Encrypting your SWAP
Ecryptfs-utils has a utitlity  which depends on. However, this utility is currently Ubuntu centric. You should setup an encrypted swap by installing and edit    which has an example of an ecrypted swap in it.

Also note, you need to add dm-crypt to the boot run level with:

You can find a version of  which works with gentoo.

External resources

 * eCryptfs on the Arch wiki