I have read the previous posts about using the RequireHttpsAttribute to secure individual controllers:
ASP.NET MVC RequireHttps in Production Only
but is the
Just to bring this answer upto date for MVC 3 and above use the following in your Filterconfig.cs file within the App_start folder
filters.Add(new RequireHttpsAttribute());
Obviously you will need your servers IIS configured to use a valid SSL certificate, cheap certs can be purchased here: https://www.namecheap.com/ i think the last time i purchased one it was $9 per domain per year.