dropbear-initramfs Permission denied (publickey)

I'm having issues unlocking an encrypted disk over ssh using dropbear. I've followed this guide to set it up, but I just end up getting Permission denied (publickey) error I copied the public key from my machine ~/.ssh/id_rsa.pub to the server /etc/dropbear-initramfs/authorized_keys and updated with update-initramfs -u -k all The config of /etc/dropbear-initramfs/config currently have this content: DROPBEAR_OPTIONS="-I 120 -c /bin/cryptroot-unlock" I also tested with the config from the article DROPBEAR_OPTIONS="-RFEsjk -c /bin/cryptroot-unlock" --- Using SSH, I've tried specifying the identity key (-i), tried with no username, server machine username, my machine username etc... I simply cannot get past the Permission denied error.