Encrypt hard drive with /boot encrypted

[Marcos Alano]

There is some articles over the Internet (like http://www.pavelkogan.com/2014/05/23/luks-full-disk-encryption/) which explains how it's possible to encrypt all the hard drive including the /boot directory and use GRUB to decrypt, so GRUB acts like a pre-boot authentication. If you encrypt /boot this improve security against kernel tempering, so should be considered.