To force SSL logins and the administration interface, edit wp-config.php and add these before the “/* That’s all, stop editing! Happy blogging. */” line:
| 
					 1 2 3 4  | 
						define('FORCE_SSL_LOGIN', true); define('FORCE_SSL_ADMIN', true); /* That's all, stop editing! Happy blogging. */  | 
					
You must set up Apache to use SSL of course.
A lot more info can be found here: