Will ecryptfs-protected home partition backup be unreadeable after restoring it to a new ubuntu install?

Question

I have a little problem here. I've just finished to set up my automatic backup system using Duplicity and Déja Dup. I backup my files to my server using SSH. After some testing, i've checked that I can still open them and see their content as before (files are not wrapped due to encryption).

What I would like to know is if I restore my files on a new Ubuntu install that hasn't my ecryptfs Private.sig file, will they become unreadable? If yes, do I need to also backup the .ecryptfs directory?

I will wait for your responce.

Thanks

Integrated-circuit

Answer 1

Yes, you need the Private.mnt & Private.sig files are mandatory unless you simply copy the files out of the ~/Private folder into a folder on the new machine via a nfs mount or samba share.

If either of those files becomes missing, it'll never work again because you've lost the mount information and the encryption key which is hashed with your password.

The encrypted home folder works virtually the same. You need to preserve the hash file and mount points, etc.

If you copy the encrypted files out of the unlocked folder into another folder that is shared but encrypted it's basically only in the clear while it's transiting the network and no intermediate copies would be generated. I don't know how high of a security you need, but it's the easiest way to to move the file and not keep a secondary copy or jack with the originals/try to kludge the originals into working in another location.