Using PHPMyAdmin to administer Amazon RDS

I can't get PHPMyAdmin to connect to my Amazon RDS instance. I've granted permissions for my IP address to the DB Security Group which has access to this database I'm trying to access. Here's what I'm working with...

    $cfg['Servers'][$i]['pmadb'] = $dbname;
    $cfg['Servers'][$i]['bookmarktable'] = 'pma_bookmark';
    $cfg['Servers'][$i]['relation'] = 'pma_relation';
    $cfg['Servers'][$i]['table_info'] = 'pma_table_info';
    $cfg['Servers'][$i]['table_coords'] = 'pma_table_coords';
    $cfg['Servers'][$i]['pdf_pages'] = 'pma_pdf_pages';
    $cfg['Servers'][$i]['column_info'] = 'pma_column_info';
    $cfg['Servers'][$i]['history'] = 'pma_history';
    $cfg['Servers'][$i]['designer_coords'] = 'pma_designer_coords';

    /* Uncomment the following to enable logging in to passwordless accounts,
     * after taking note of the associated security risks. */
    // $cfg['Servers'][$i]['AllowNoPassword'] = TRUE;

    /* Advance to next server for rest of config */
    $i++;
}

    $cfg['Servers'][$i]['auth_type'] = 'http';  //is this correct?
    $cfg['Servers'][$i]['user'] = 'MASTER-USER';
    $cfg['Servers'][$i]['password'] = 'MASTER-USER-PASSWORD';
    $cfg['Servers'][$i]['hide_db'] = '(mysql|information_schema|phpmyadmin)';
    /* Server parameters */
    $cfg['Servers'][$i]['host'] = 'MY-DB.us-east-1.rds.amazonaws.com';
    $cfg['Servers'][$i]['connection_type'] = 'socket';
    $cfg['Servers'][$i]['port'] = PORT;

I'm not sure if my configuration is correct.

I'm getting this error:

#2013 - Lost connection to MySQL server at 'reading initial communication packet', system error: 110

Does anyone have any advice?