$ sudo apt install ecryptfs-utils

$ ecryptfs-setup-private --nopwcheck --noautomount

$ ecryptfs-mount-private
Enter your login passphrase:
Inserted auth tok with sig [fd7bf4e96709610d] into the user session keyring
mount: No such file or directory

$ keyctl show
Session Keyring
 129407649 --alswrv   1000  1000  keyring: _ses
 779489152 ----s-rv      0     0   _ user: invocation_id