Not every person on Internet is honest and kind. So: it's best to allow to edito your page only persons you trust.

You can protect /edit.php script with the following .htaccess file:

Options -Indexes                                                                                                                                             
AuthType Basic                                                                                                                                               
AuthName " - CMSWIKI"                                                                                                                          
AuthUserFile "/your-path-to-htpasswd-dir/.htpasswd"                                                                                                               
DirectoryIndex view.php                                                                                                                                      
<Files "edit.php">                                                                                                                                           
    require user dci                                                                                                                                         

When attemting to edit current page you will be asked for login & password. An instruction how to generate .htapsswd file:

htpasswd -b -c /your-path-to-htpasswd-dir/.htpasswd \
	login password

“Perfection is finally attained not when there is no longer anything to add but when there is no longer anything to take away.”
-- Antoine de Saint-Exupery