Is there any way to fully encrypt my hard-drive AFTER an installation of Linux Mint?

I'm askin myself, is there any software who can encrypt my whole hard drive with Linux Mint 17.3 on it AFTER the installation? Like TrueCrypt for Windows?! If not and I've to reinstall everthing is there any possibility to safe all my datas (including the installed programs) to restore it after an successful installation of an fully encrypted OS? Maybe with this tool (included in Linux Mint): ???