Wp Private Access adds an http authentication dialog using WordPress users database. Wp private is particularly useful for testing blogs and websites based on WordPress keeping them visibile only to authorized users.
The plugin provides also with a template page for unauthorized access (401 error).

Wp Private Access

Wp Private Access adds an http authentication dialog using WordPress users database

Good caching policies is one of performance’s best friends, and it can be your new best friend too. Get friendly with intermediary and browser caches by taking control over your WordPress powered website’s HTTP <code>Cache-Control</code> headers.
This is not a caching plugin in itself, but will enable you to leverage existing standard compliant caching systems better. You can set different policies for different kinds of pages to suite your website’s needs. The Cache-Control for WordPress plugin allows you to set different policies for shared/intermediary and private caches. The plugin sets some sensible defaults for a medium traffic blog that publishes an update or two per week.
You can safely set long <code>Cache-Control</code> times as the <code>max-age</code> values is lowered automatically before a scheduled post is about to be published.
Private pages (logged in users, the admin interface, etc.) will not be cached.
The plugin has <a href="https://www.ctrl.blog/entry/wp-cache-control-documentation.html" rel="nofollow ugc">extensive documentation</a>.

Cache-Control

Configurable HTTP Cache-Control response headers for webpages generated by WordPress.

Wp Private Access vs Cache-Control