LUKS (Linux Unified Key Setup) is the de facto standard encryption method used on Linux-based operating systems. As we saw in previous tutorials, when we want a partition or raw disk encrypted using LUKS to be automatically unlocked at boot, we need to enter a dedicated line into the /etc/crypttab file. Doing so, we are prompted to provide the encryption password interactively. This is quite straightforward on laptop or desktop machines, but how can we unlock a volume on an headless server? One solution is to use dropbear to get ssh access at an early boot stage, in the initramfs, in order to provide the volume password.