Notes on DPAPI and ProfileKeyManager

Profile Key Manager: A Swiss Knife…
How to Configure Encryption Keys for Profiles System Data
http://msdn.microsoft.com/en-us/library/aa544806.aspx
Profile Key Manager Command Line Utility Reference
http://msdn.microsoft.com/en-us/library/aa545396.aspx
Windows Data Protection
http://en.wikipedia.org/wiki/Data_protection_API
http://msdn.microsoft.com/en-us/library/ms995355.aspx

Web Farm Considerations
http://man.ddvip.com/web/bsaspnetapp/LiB0068.html

How To: Encrypt Configuration Sections in ASP.NET 2.0 Using DPAPI
http://msdn.microsoft.com/en-us/library/ms998280.aspx