monte@machin-shin:/srv/data/VirtualBox/MyDataScienceToolbox$ sudo chmod 0600 /srv/data/VirtualBox/MyDataScienceToolbox/.vagrant/machines/default/virtualbox/private_key 
[sudo] password for monte: 
monte@machin-shin:/srv/data/VirtualBox/MyDataScienceToolbox$ ls -al /srv/data/VirtualBox/MyDataScienceToolbox/.vagrant/machines/default/virtualbox/total 6
drwxrwx--- 1 root plugdev  456 Jul 14 19:40 .
drwxrwx--- 1 root plugdev    0 Jul 14 19:02 ..
-rwxrwx--- 1 root plugdev   10 Jul 14 19:40 action_set_name
-rwxrwx--- 1 root plugdev   36 Jul 14 19:40 id
-rwxrwx--- 1 root plugdev   32 Jul 14 19:40 index_uuid
-rwxrwx--- 1 root plugdev 1675 Jul 14 19:40 private_key
monte@machin-shin:/srv/data/VirtualBox/MyDataScienceToolbox$