  The National Identity Document is a fundamental piece of documentation for
the identification of citizens throughout the world. That is precisely the case
of the DNI (Documento Nacional de Identidad) of Spain. Its importance has been
enhanced in recent years with the addition of a chip for the authentication of
users within telematic administrative services. Thus, the document has since
been called: electronic DNI or simply DNIe. Sensitive user information is
stored in that integrated circuit, such as personal and biometric data, along
with signature and authentication certificates. Some of the functionalities of
the DNIe in its current version at the time of writing this work have been
implemented for years in the DNI 3.0 version launched in 2015, and therefore
have already been extensively studied. This work provides a theoretical and
practical compilation study of some of the security mechanisms included in the
current DNIe and in some of the applications that require its use. It has been
carried out using only mobile devices and generic card readers, without having
any type of privileged access to hardware, software or specific documentation
for the interception of packets between the DNIe and the destination
application. In other words, it is an exploratory analysis carried out with the
intention of confirming with basic tools the level of robustness of this very
important security token.
