At the beginning of booting Linux a special program asking for passphrase is loaded if your linux is installed to encrypted-lvm, but this can be a security problem if the special program gets infection by virus of Microsoft Windows, maybe modified, sending passphrase to somewhere of Windows partition. But install the passphrase program to a USB stick is much safer due to it is more isolated than in the hard drive. I want to know how to make a bootable USB for entering the passphrase that I can login Linux?
How to install passphrase screen to a USB stick?
grub2;boot loader;luks