Usuario.cs

using System;
using System.Reflection;

[assembly:AssemblyVersion("1.1.0.1")]
[assembly:AssemblyKeyFileAttribute("MiLlave.snk")]
[assembly:AssemblyDelaySignAttribute(true)]

public class Usuario : Persona
{
    private string nombreUsuario;
    private string password;

    public string NombreUsuario {set; get;}
}