$ sudo apt-get remove libksba8 

Uninstall libksba8 including dependent package

If you would like to remove libksba8 and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove libksba8 

Use Purging libksba8

If you use with purge options to libksba8 package all the configuration and dependent packages will be removed.

$ sudo apt-get purge libksba8 

If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.

$ sudo apt-get purge --auto-remove libksba8 

See Also,