2x Security plugin request

#1.
I was just wondering if theres a plugin which could do the following:
I want to make a category “private” so that only the administrator can post in that category but everyone else can still view the posts in the category.

This would work well for people who want a “site announcement” type category 🙂

#2.
Another idea is, if there is already a plugin which could make certain pages “private” and you would need to login/register to view them.
The idea behind this is i’m using a contact form from takayukister and guests can use it. I would want to make it useable for registered users only.