Through the past 20 years, Computer sciences evolution has changed the world at all levels, economical, medical, social, etc. Nowadays, humans likely spent time on the Internet more than real world, and lead online social, economic and administrative activities. Therefore, the mapping between the virtual and real existence were obligatory, leading the community towards authentication and privacy needs. The Digital Identity was then born and involved into the Self-Sovereign Identity (SSI) to prove online users' and contents authenticity by preserving privacy and autonomy. This paper tracks the SSI origins and principles, it also explores some associated applications and the common architecture. It even overviews the Moroccan digitalization project's objectives, and proposes an SSI based architecture, entitled “Mouatten4.0”, to allow citizens to make online authenticated transactions.