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

External resources

 * eCryptfs on the Arch wiki