With the law 59/2003 , 19 December, electronic signature, the electronic DNI becomes a reality. It aims to achieve various advantages:

The fact that the private key is only known by its owner allows us to achieve two important things:

• Create a document that certifies the identity of the citizen not only in the physical world, but also before telematic transactions, allowing sign all kinds of electronic documents. Using a secure device signature, electronic signature is made through the electronic DNI will impact equivalent to those of a handwritten signature.
• Electronic DNI issuing in a single administrative act, thus reducing the time spent for its acquisition.
• Interoperability with European projects digital identification.
• Build confidence in electronic transactions.
• Endorsement by all public administrations and entities linked Public Law or dependent on the same the use of electronic DNI. (E.g. to make the statement of income, request a certificate of registration, to register in the register of births or claim the right to pension).

The national identity document electrónico looks similar to a credit card, and what gives you the ability to identify the citizen, as well as offer the possibility of signing electronic documents, will be what has been called Public Identity certificate. This certificate will be incorporated into the DNI, and in addition to identify the citizen (authentication), ensure that the information has not been altered (integrity) and that the citizen has made the transaction (non-repudiation).