In today’s society, digitalization is progressing quickly, with one of the objectives being to provide easier access to digital identifiers. How can we be sure of one’s identity without physical proof though? Classical digital signatures are well established in several digital technologies (e.g., Covid Certificate), but run the risk of exposing valuable personal information. New proposals are on the way, which provide techniques to protect this information by leveraging modern mathematical frameworks (e.g., Zero-Knowledge Proofs).