>>> challenge = <1896.697170952@postoffice.reston.mci.net>
>>> received = b913a602c7eda7a495b4e6e7334d3890
>>> digest = b913a602c7eda7a495b4e6e7334d3890
>>> challenge = <1896.697170952@postoffice.reston.mci.net>
>>> received = b913a602c7eda7a495b4e6e7334d3890
>>> digest = b913a602c7eda7a495b4e6e7334d3890