How much security is really needed on a "private" website? [closed]

Question

I'm asking this as I maintain a small website for a fairly isolated group of people (no more than 80). It currently has a simple log in function (e-mail, password) and the data that is "protected" is merely contact information to our members (telephone, address, e-mail). The website is written in PHP and use My SQL.

These last couple of days, I've been reading through the forums and other sites about web site security, since I would like to enhance it on our site. Right now the security consists of SQL-injection protection and MD5-hashed passwords stored in a database. This feels abit inadequate but I also feel that it's easy to take it TOO far. I mean it's not exactly nuclear launch codes here, but data people usually feel abit unconfortable to display online. The site itself is hosted by a fairly renown web host.

The only threat I can see right now are pranksters stumbling across the site and trying some of their home made concotion?

So I thought somewhere in the middle would suffice. Like

• SQL-injection protection (enhance if needed)
• Stronger hash method with salt
• XSS-protection
• DDoS-protection
• SSL when accessing the member area

What do you more experienced people out ther think?

Update: I would like to add that I do everything myself and there is no budget for buying fancy crypto techniques or hiring professional programmers.

Answer 1

To enhance security for SQL injection, you must see:

• Best Way to Prevent SQL Injection

It would tell you to use PDO, parameterized queries.

To learn about general security issues, see this post which covers a lot:

• PHP Security Guide (By PHP Security Consotium)

Audit your site in terms of security using:

• OWASP

And

• PHPSec

phpSec is a open-source PHP security library that takes care of the common security tasks a web developer faces.

Answer 2

Add CSRF vulnerability protection to your security list