object getCallerPublicKey() {
    const string CLAIMTYPE_RSA =  http://schemas.microsoft.com/ws/
        "2005/05/identity/claims/Rsa";
    AuthorizationContext ctx =    
        ServiceSecurityContext.Current.AuthorizationContext;
    foreach (ClaimSet cs in ctx.ClaimSets) {
        foreach (Claim c in cs) {
            if (Rights.Identity == c.Right &&
                CLAIMTYPE_RSA == c.ClaimType) {
                    return c.Resource;
            }
        }
    }
    throw new Exception("Expected an RSA claim");
}

string hashPublicKey(object rsaKey) {
    RSAParameters keyParams = ((RSA)rsaKey).ExportParameters(false);
    SHA256Managed hashAlg = new SHA256Managed();
    hashAlg.TransformBlock(keyParams.Exponent, 0,
        keyParams.Exponent.Length, null, 0);
    byte[] hash = hashAlg.TransformFinalBlock(keyParams.Modulus, 0,
        keyParams.Modulus.Length);
    return Convert.ToBase64String(hash);
}

public class Notepad : INotepad {

    static Dictionary<string, string> map =
        new Dictionary<string, string>();

    public string GetNote() {
        string userId = getUserIdentifier();
        lock (map) {
            if (map.ContainsKey(userId))
                 return mapUserIdToNotes[userId];
            else return null; // new user
        }
    }

    public void SetNote(string data) {
        string userId = getUserIdentifier();
        lock (map) {
            map[userId] = data;
        }
    }

    string getUserIdentifier() {
        string ppid = getCallerPPID();
        string publicKeyHash = getCallerPublicKeyHash();
        return ppid + publicKeyHash;
    }
    // ...
}

          <connectionStrings>
  <clear/>
  <add name="asp"
       connectionString="integrated securiyt=sspi;database=myaspnetdb"
       providerName="System.Data.SqlClient" />
</connectionStrings>

<system.web>
  <!-- other entries omitted for brevity -->
  <membership defaultProvider="MyProvider">
    <providers>
      <clear/>
      <add name="MyProvider" 
        type="System.Web.Security.SqlMembershipProvider, System.Web, 
              Version=2.0.0.0, Culture=neutral, 
              PublicKeyToken=b03f5f7f11d50a3a" 
        connectionStringName="asp" 
        applicationName="MyApplication" 
        enablePasswordRetrieval="false" 
        enablePasswordReset="true" 
        requiresQuestionAndAnswer="true" 
        requiresUniqueEmail="false" 
        passwordFormat="Hashed" 
        maxInvalidPasswordAttempts="5" 
        minRequiredPasswordLength="8" 
        minRequiredNonalphanumericCharacters="2" 
        passwordAttemptWindow="10" 
        passwordStrengthRegularExpression="" />
    </providers>
  </membership>
</system.web>

using System;
using System.Runtime.InteropServices;

// fsp == file system properties
// usage: fsp propertyPageName filename
//        fsp security c:\autoexec.bat
class DisplayFileSystemPropertySheet {
    static void Main(string[] args) {
        if (2 != args.Length) {
            printUsage();
            return;
        }
        string page = args[0];
        string path = args[1];

        if (!SHObjectProperties(IntPtr.Zero,
            ShellObjectType.FilePath, path, page)) {
                Marshal.ThrowExceptionForHR(
                    Marshal.GetHRForLastWin32Error());
        }
        Console.WriteLine("Press any key to continue...");
        Console.ReadKey();
    }

    static void printUsage() {
        Console.WriteLine("Usage: fsp propertyPageName filename");
        Console.WriteLine("Example: fsp Security c:\\autoexec.bat");
    }

    enum ShellObjectType : int {
        PrinterName = 1,
        FilePath = 2,
        VolumeGuid = 4
    }

    [DllImport("shell32.dll", CharSet = CharSet.Unicode,
               ExactSpelling = true, SetLastError = true)]
    [return: MarshalAs(UnmanagedType.Bool)]
    static extern bool SHObjectProperties(IntPtr hwndParent,
        ShellObjectType type, string name, string page);
}