title: System.PlatformNotSupportedException AesCryptoServiceProvider
body: <p>I've got the following problem.</p>
  
  <p>I've created a class that uses AesCryptoServiceProvider to encrypt and decrypt some data. I'm using the class in a SharePoint WebPart and everything works fine. I'm also using the same class on the same webapplication in a custom SharePoint webservice and every time the constructor of the System.Security.Cryptography.AesCryptoServiceProvider is called it throws a System.PlatformNotSupportedException with the following stack trace.</p>
  
  <pre><code>System.PlatformNotSupportedException: The specified cryptographic algorithm is not supported on this platform.
     at System.Security.Cryptography.CapiNative.AcquireCsp(String keyContainer, String providerName, ProviderType providerType, CryptAcquireContextFlags flags, Boolean throwPlatformException)
     at System.Security.Cryptography.AesCryptoServiceProvider..ctor()
     at m2009_wu.ProvisioningLibrary.ConfigManager..ctor()
  </code></pre>
  
  <p>I've tried to compile the webservice and the library with the class in it for different platforms without any change.</p>
  
  <p>The system my development environment is running on is a Windows Server 2008 Standard SP1 x64 with Microsoft Office SharePoint Server 2007 SP2 x64 and Visual Studio 2008 SP1. The .Net Framework 3.5 SP1 is installed on the server.</p>
  
  <p>I'd be greatful if anyone could point me in the right direction.</p>
  
  <p>Kind regards
  Rene Windegger</p>