dm520 login: root
root@dm520:~# update-rescue -v
Warning: Could not read CA!
Warning: Please consider updating your rescue loader!
[*] Downloading 'http://dreamboxupdate.com/download/recovery/dm520/release/rescue-image-dm520.bin.sig'
[*] Downloading 'http://dreamboxupdate.com/download/recovery/dm520/release/rescue-image-dm520.bin'
[*] Verifying signature of 'rescue-image-dm520.bin'
/usr/sbin/update-rescue: line 38: gpgv: not found
Fatal: Failed to verify signature
