Ignore Required attribute when saving on edit page

I have a model class that has a couple of required fields:

public class UserMetadata
{
   [Required(ErrorMessage = "Please enter a name.")]
   public string Name { get; set; }

   [Required(ErrorMessage = "Please enter a password.")]
   public string Password { get; set; }
}

On the create view, if I don't give a name and/or password, then the validation summary errors appears. All nice and good. For the edit view, I'm only displaying the 'Name' field - I don't to show the 'Password' field.

When I save my changes on the edit page, the validation summary error appears saying that I must enter a password.

How can I control the validation of the password field, so that for the edit view, it should not bother with it? Or, am I approaching this the wrong way? I still want the 'Name' field validation to work on the edit view.

EDIT:

For my MVC project, I'm using Entity Framework. Thus, I have a 'UserMetadata' class defined so that I can attached things like '[Required]' onto certain fields on the 'User' class (which is in the EDMX file).

I should also explain that I'm using a view model eg 'UserEditViewModel' which has a property 'User' attached to it. So on my post:

[HttpPost]
public ActionResult Edit(UserEditViewModel inputViewModel)
{

    if(ModelState.IsValid) { inputViewModel.User blah.... }

}

Think I rushed a bit when typing this question. Any other missing information you think is important, then please give me a shout.

Cheers. Jas.