.NET exceptions I can throw for Not Authorized or Not Authenticated

I have parts of code where I want to throw an Exception whenever a user is not authenticated/not authorized.

So instead of writing my own NotAuthenticatedException and NotAuthorizedException, I was wondering if there are not already some C# standards for these.

I can imagine a lot of programs throw similar Exceptions, and it would not be very useful if everyone 'writes their own wheel' again.

You could also use UnauthorizedAccessException for authorization violations

Use the C# AuthenticationException or InvalidCredentialException class.

https://docs.microsoft.com/en-us/dotnet/api/system.security.authentication.authenticationexception

To avoid reinventing the wheel, I'd use PrincipalPermission.Demand or PrincipalPermissionAttribute.

A SecurityException will be thrown for you if the demand fails.

If you do want to explicitly throw an exception rather than using PrincipalPermission.Demand, you could consider reusing the existing type System.UnauthorizedAccessException, which is described in MSDN as:

The exception that is thrown when the operating system denies access because of an I/O error or a specific type of security error.

It's your app rather than the OS that's denying access, but perhaps close enough.