  The Public Key Infrastructure existed in critical infrastructure systems
since the expansion of the World Wide Web, but to this day its limitations have
not been completely solved. With the rise of government-driven digital identity
in Europe, it is more important than ever to understand how PKI can be an
efficient frame for eID and to learn from mistakes encountered by other
countries in such critical systems. This survey aims to analyze the literature
on the problems and risks that PKI exhibits, establish a brief timeline of its
evolution in the last decades and study how it was implemented in digital
identity projects.
