About
An identity is the identifier of an entity. (id + entity = identity)
The key is a mathematical entity, while the owner – and the connection between owner and key – are not.
If we generalize an identity is just an identifier (key).
Key
The identity unique key is called a principal or a subject
Type
An identity may be:
- anonymous (we don’t know anything about this person/device yet),
- or named (we know something about them such as an email address / id )