Which package provides this login screen?

Question

I would like to identify the package that provides the following login screen:

Answer 1

According to the wiki, the package is unity-greeter and it is part of lightdm, these are the relevant files for customization

/usr/share/lightdm/lightdm.conf.d/*.conf
/etc/lightdm/lightdm.conf.d/*.conf
/etc/lightdm/lightdm.conf

Specifics can be found at the wiki link.