The Digital Mobile Key (DMK) is the national mobile eID solution which allows citizens to digitally authenticate themselves in public and private websites as well as digitally sign documents, in a secure manner. It was developed to address the increasing demand of mobile solutions, as well as to offer a more user-friendly alternative to the Citizen Card mechanism, which requires a smartcard reader.
The Digital Mobile Key authentication and signature is done through a permanent password (PIN) and a temporary security numeric code, automatically generated and sent by SMS, email or a dedicated app.
By the end of 2018, protocols with some of the major private service providers (banking, telcos, utilities) led to a significant surge of DMK’s subscriptions. The adoption of the DMK by service providers with recurrent interactions with Portuguese citizens has proven to be fundamental to the increased adoption of DMK, as it promptly became the preferred option of authentication within the national eID schemes, surpassing for the first time the “old” Citizen Card.
In 2020, this tendency remained unchanged, as the number of DMK subscribers continues to grow and it remains as the chosen eID mechanism in the national scene, and currently there are 2,36 million registered users and about 150 (public and private) entities using this mechanism in their websites. It’s worth mentioning that the DMK, being a simple and user-friendly solution, has proven particularly relevant during the COVID19 pandemic following on the need to increase the digital services interaction, due to the restrictions on face- to-face service attendance.
The DMK provides public and private organizations with a standardized and open API which supports authentication and signature reuse across government and third-party service providers, thus allowing significant savings in terms of developing costs. Also, the DMK is fully compliant with the European eIDAS Regulation, being recognized by the European Commission as a highly secure eID mechanism.

https://www.autenticacao.gov.pt/a-chave-movel-digital

• Portugal

Citizens are more and more prone to use mobile solutions, and therefore the possibility to use the smartphone to digitally sign documents and interact with public administration and private services mean a significant step in convenience and usability for citizens.
From the technological point of view, the Digital Mobile Key solution is shareable and reusable, and it is in fact being adopted by several public and private organizations in Portugal, that wish to provide different and more user-centric methods of authentication to their end-users. This tool is based on the open standard SAML specification and is integrated with the Portuguese National Identity Provider, and its source code can be reused by public or private organization under the EUPL license. This means that the technology and its specifications are available free of charge and there are manuals teaching how to install it.
The Digital Mobile Key has received good criticism from the public organizations that are adopting it for their own services.
For the abovementioned, the transferability of the Digital Mobile Key may be done in a simple process.

The Administrative Modernization Agency (AMA), which is the public body responsible for digital government and administrative modernisation and simplification, is in charge of monitoring, making the necessary additional testing exercises and exploring and implementing improvements to the DMK when applicable. The expertise of AMA’s responsible team, and the fact that the DMK is totally embodied in the mission and strategy of public services modernization performed by AMA, guarantees the sustainable governance of this solution.
Its sustainability is further assured by a strong political support of the DMK as a central building block of the Portuguese eID Framework - the constant addition of new features (e.g. mobile eSignature), the swift integration of the DMK in digital public services delivered by different areas of governance and its steady adoption by the private sector (e.g. banking, utilities) are some of the positive outcomes of setting eID as a political priority.
The DMK also benefits from specific legislation providing it legal support (law nº. 37/2014, of 26 June 2014, and law nº32/2017, of 26 June).
It’s also worth mentioning that AMA promotes a permanent communication strategy to disseminate the DMK, which duly reflects on the growing number of registrations and authentications.
In terms of financial sustainability, the DMK is fully funded by the National State Budget, through AMA's own budget. In this way, the whole cycle of development, maintenance, support and evolution of the Digital Mobile Key is ensured by AMA, using internal resources and subcontracting.
The costs inherent to the use of this mobile authentication mechanism by public entities are supported by AMA, while the costs arising from the use by private entities are supported by the companies themselves. This financial model is formally described in the (mandatory) protocols signed between AMA and the entities adhering to the DMK.

The Digital Mobile Key was developed to address the increasing use of mobile devices by citizens and subsequent demand of mobile solutions, as well as to offer a more user-friendly alternative to the Citizen Card mechanism, which requires a smartcard reader. The Digital Mobile Key provides a simple and secure way to access digital services, totally free of charges and operating 24/7, allowing citizens to both authenticate themselves and use qualified electronic signatures when interacting with both the public and private sector. The collaboration between the State and the private sector, with the growing adoption of the DMK by private service providers with recurrent interactions with Portuguese citizens, has proven fundamental to the increased uptake of DMK, which currently stands as the preferred option of authentication within the national eID schemes and is duly recognized as a trustworthy solution by its end-users. In face of the above, we believe that the CMD is aligned with the WSIS values expressed in the Genebra Declaration (2003), as it aims to simplify and foster the use of technology through a citizen-centred approach that aims to address the user’s real needs and also bridge the digital divide. Furthermore, the DMK foresees a transparent collaboration between the public and private sector that promote equally accessible digital services, a shared responsibility by stakeholders and environmental benefits that arise from the reuse of solutions and resources.