It prevents your blog directories from listing requests with redirect to home page, removes unused txt, screenshot files from plugins directories.
Silence is Golden Guard plugin prevents WordPress blog directories from listing if visitor types just directory name as the URL, e.g. http://yourdomain/wp-content/plugins/ Plugin can automatically check WordPress site state and fix it if needed once a day. The checking are: * .htaccess file. If it has not Options -Index line, plugins makes backup copy and adds Options -Indexes line into .htaccess file in the WordPress root directory. * Plugin can check if empty index.php file exists in the every directory. If index.php file doesn't exist, plugin creates one with comments line 'Silence is golden' as WordPress does. This check and fix are useful as many plugin authors do not put index.php files into their plugin directories. Redirect to the site root option from index.php call is available. * Other functions: * remove unused files (readme.txt, screenshot-.) from plugins folders, which could expose plugin versions to attacker. * remove WordPress version information from blog pages. You can find more infomation here at shinephp.com
There is a very strong recommendation to make full backup of your blog before you activate SIG plugin. If you have development copy of your blog at the same webhost I recommend you to give a SIG plugin first try at the test environment as there are small amount of incidents when with redirection to site root option turned on automatically created empty index.php file caused endless redirect loop and prevents site loading. It could be the case if you use child theme and theme_name-child folder has not its own index.php file and some other cases which are not isolated yet.