password for filename encryption

The ecryptfs_fnek_sig is not the password - it is a signature of the authentication token used to enable file encryption key decryption and used put in the user's keyring for mounting the encrypted folder.

Are you attempting to encrypt an user's home directory or just a subfolder? Are you wanting it to manually mount it or have it automount on login?

automount,
I want to encrypt an entire flash drive.

Could I use the same key for both content and filename?

The same key can be used.

I'm not sure about automounting an encrypted flash drive though. Automounting is typically associated with user login.

There are also some bugs with network storage mounts - don't know if they would apply in this situation.

Hello,

for external drives/USB ..etc I'm using the cryptsetup utility.

Be aware that this method will destroy any data in the USB stick/drive. Make sure to take a backup of the contents.

First install cryptsetup

    sudo apt-get install cryptsetup

then open the 'Disks' utility and click the external USB you are interest in. Click the 'gears' icon next to the 'play' icon and select Format. There you will select 'Encrypted with LUKS + Ext4'.

It will ask for a password and after this the entire USB will be encrypted.

After, you can safely remove the drive, plug in again and you will see the prompt for the password in order to decrypt the drive. You can select to decrypt automatically (auto-mount/decrypt) if you want (it's the third option if I remember correctly), every time you plug this USB in this specific PC/Operating System.

Regards
NickTh

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