Security dilemma

Hi!

A few months ago started doing web design and I’ve been hosting my clients on a shared server account, there had been no trouble because I had not used anything but HTML, a few PHP code and some Flash movies.

But a few days ago, a good client asked to me about a dynamic news posting service for the use of his employees. I had many alternatives for the news posting, but I was completely lost when I came to the passwords thing. I’ve found a lot of information about coding and encryption, but I’m clueless about implementing one of these solutions on the site (or more specifically on the shared server) without having to make a big moving to a home made server.

Extra information: board information encryption -> not needed, server: Win 2003 IIS, page programmed on php, and html.

Thanks.