WHY A SCALABLE EID IS NEEDED: LESSONS FROM PORTUGAL AND THE CHALLENGE FOR UKRAINE IN INTEGRATING INTO THE EUDI WALLET

Abstract

The article is devoted to a quantitative analysis of the dynamics of
electronic identification (eID) usage in Portugal with the aim of developing an
indicative load scenario for Ukraine’s future integration into the EUDI Wallet
ecosystem. The relevance of the study is driven by the ongoing expansion of digital
public services across the European Union, the implementation of the updated
eIDAS 2.0 regulatory framework, and the need to ensure the scalability of national
digital identification systems in the context of a growing number of electronic
interactions. Based on the open dataset “Autenticações eletrónicas realizadas”
covering the period 2019-2024, a linear regression model was developed in which
the number of electronic authentications is explained by a trend component,
seasonal dummy variables for August, November, and December, as well as
structural break indicators DID_STRESS_2022 and EIDAS_2024. Model quality
was assessed using the coefficient of determination, relative root mean square
error, statistical significance tests for the parameters, and the Durbin-Watson test.
The modelling results indicate the presence of sustained long-term growth in
demand for electronic identification services, regular seasonal fluctuations, and
several statistically significant structural changes. The proposed model
demonstrates high explanatory power (R2 ≈ 96%) and an acceptable level of
forecasting error, capturing the combined effects of trend, seasonality, and onetime shocks. Based on the estimated model, a forecast for 2025-2027 was generated,
indicating further growth in the number of electronic authentications and the
persistence of characteristic end-of-year load peaks. The findings suggest that the
Portuguese trajectory may serve as a useful benchmark for assessing the prospects
of Ukrainian digital identity infrastructure development in the context of integration
into the EU Digital Single Market and the implementation of the EUDI Wallet. The
study also identifies its main limitations and outlines directions for future research
involving panel and dynamic modelling approaches.

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