What are the levels of the evidence factor (IE.a to IE.d) in identity proofing?
IE.a no evidence or none with probative value; IE.b evidence with an identifier and security features; IE.c evidence recognised in the context and checked for authenticity (a valid identity document or an equivalent or higher-rated E-ID); IE.d additionally state-recognised evidence with the person's physical features is checked.
The questions: Is the evidence genuine and valid? Does it come from a reliable and recognised source?
| Value | Meaning | Example |
|---|---|---|
| IE.a | No evidence, or not meaningful | Self-declared name in a form |
| IE.b | Evidence present: contains an identifier and security features | A customer card or utility bill with a number and some security print |
| IE.c | IE.b, plus recognised in the context and checked for authenticity: a valid identity document, or electronic proof of an equal or higher-rated identity (E-ID) | A passport whose security features were verified |
| IE.d | IE.c, plus state-recognised evidence with physical features of the person is checked | A passport or ID card whose photo (or chip biometrics) is compared with the person |
The ladder climbs in two directions: trust in the source (from nothing to a state-issued document) and binding to the body (only IE.d carries features such as a photo that tie the document to the person presenting it). Note that an existing E-ID at the same or a higher level can count as IE.c evidence, which lets one strong identity bootstrap another.
Go deeper:
Identity document (Wikipedia) — security features and the role of state-issued IDs.