What is a "reliable source" (verlässliche Quelle), and how does the newer eIDAS term "authentic source" sharpen the idea?

A reliable source is any information source that is considered trustworthy for a given situation, such as identifying a person; eIDAS 2024/1183 adds the "authentic source", a repository run by a public or private body that holds attributes about a person or object and is recognised as the primary source for them.

The word "reliable" is context-dependent: the source is trusted for a concrete situation. Examples are registers, deeds and public authorities.

The EU regulation eIDAS defines the idea in two generations:

• eIDAS 2015/1502: a reliable source is any source that provides accurate data, information or evidence that can be used to prove an identity.
• eIDAS 2024/1183 introduces the authentic source: a data store or system, operated under the responsibility of a public or private body, that contains and provides attributes about a natural or legal person or an object, and that is considered the primary source for that information, or is recognised as authentic by EU or national law.

The shift from "reliable" to "authentic" reflects the move from paper evidence towards querying the registers directly: instead of showing a photocopy of your diploma, the university's register attests the degree.

Go deeper:

• Implementing Regulation (EU) 2015/1502 (EUR-Lex) — the assurance-level regulation that defines the authoritative source and the levels low, substantial and high.