I am trying a very simple provider hosted app. it work fine during debug but when i try to published to iis and got this error

System.Security.Cryptography.CryptographicException: Access denied. 

on TokenHeper.cs line below

private static readonly X509Certificate2 ClientCertificate = (string.IsNullOrEmpty(ClientSigningCertificatePath) || string.IsNullOrEmpty(ClientSigningCertificatePassword)) ? null : new X509Certificate2(ClientSigningCertificatePath, ClientSigningCertificatePassword);

• Edited by VietP 9 hours 27 minutes ago

The reason is that under the credential, the app is hosted don't have access to MachineKeys folder. A good workaround with screenshot is here...http://geekswithblogs.net/technetbytes/archive/2011/10/12/147281.aspx

Hope this helps.