What is a digital identity, and what must it be bound to in order to be usable for IAM?

A digital identity is the data object that digitally represents properties of a subject; a subject can have several, they can be linked, and each one is bound to an authentication means the subject can use to prove ownership.

Key properties:

• It is a data object for a subject, not the subject itself.
• One subject, many digital identities: your HSLU account, your Google account and your SwissPass are three digital identities of one person.
• Digital identities can be linked (identity linking), so that one can be used in place of another.
• It is bound to an authentication means (password, token, certificate); without such a binding the object is just a record about someone, not an identity anyone can log in with.

Synonyms: digital identity, electronic identity (E-Identity), user account.

Go deeper:

• Digital identity (Wikipedia) — attributes, identifiers, authentication and the policy debates around digital identities.