For an enterprise type WCF service, where potentially 10K\'s of thousands of clients will be authenticating and sending data to central servers, what is \'best\' practice when i
As blowdart mentioned, WCF Sessions are not the same as ASP.NET Sessions. You can read up on them here: http://msdn.microsoft.com/en-us/library/ms733040.aspx. Before you roll your own security, you'll want to get familiar with what WCF gives you out-of-the-box: http://msdn.microsoft.com/en-us/library/ms734736.aspx. They may get you close to your goal without writing a lot of code. Specifically, check out How to: Create a Secure Session. With secure sessions, the Client and Server cache credentials so you don't have to fully authenticate with each request. By default, you'll lose a secure session if the web server recycles. If you want a secure session that lasts through a recycle, you'll want to look at How to: Create a Stateful Security Context Token for a Secure Session.