At the cinema door
At a cinema, you say your name for a booking. That is a claim. Then the staff ask for the booking card or your phone. That is the proof.
Computer systems do the same. They ask who you say you are, then ask you to prove it.
These are the first two steps of a model called IAAA: saying who you are, then proving it.
By the end of this lesson
Note
I can explain identification (saying who you are) and authentication (proving it), with the benefit and drawback of each method.
Key words
| Word | What it means |
|---|---|
| IAAA | Four steps in secure access: say who you are, prove it, get your rights, and be recorded. |
| Identification | Saying who you are, so the system can recognise you. |
| Authentication | Proving that you are who you said you are. |
| Username | A name that identifies an account. |
| Knowledge factor | Something you know, such as a password. |
| Possession factor | Something you have, such as a card or a phone. |
| Biometric | Something you are: a body feature such as a fingerprint. |
| MFA | Multi-factor authentication: using two or more different kinds of proof. |
| Passphrase | A password made of several words. |
| Authorisation | Deciding what a logged-in user may do. It is the next lesson. |
| Token | A small device or app that makes a code for logging in. |
The cells students fill in are left blank in this preview.
Starter: what you already know
Have a go
Starter: what you already know
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
Cycle 1: identification
Identification is recognising an individual in a digital system. You say who you are. It is only a claim.
There are three ways to be identified:
Knowledge-based: something you know, such as a username.
Possession-based: something you have, such as a staff card.
Biometric-based: something you are, such as a face or a fingerprint.
Authentication
Authentication checks that the claim is true. Anyone can type a username, so the system asks for proof.
Proof can be a password or passphrase (knowledge), a phone code or token (possession) or a fingerprint (biometric).
With MFA, the system asks for two or more different kinds. A password and a fingerprint is MFA. Two passwords is not.
Worked example: benefits and drawbacks
| Method | Kind | Benefit | Drawback |
|---|---|---|---|
| Username | Knowledge: identification | Simple, free | Easy to guess, so it proves nothing |
| Password | Knowledge | Cheap and familiar | Guessed, stolen, reused, forgotten |
| Passphrase | Knowledge | Long and easy to remember | Still a secret that can be stolen |
| Card or phone | Possession | Hard to steal at a distance | Can be lost or stolen |
| Fingerprint or face | Biometric | Always with you, fast | Cannot be changed if stolen, may be wrong sometimes |
| MFA | Two or more kinds | A stolen password is not enough | Extra effort, a lost phone causes trouble |
The cells students fill in are left blank in this preview.
Check: identification and proof
Have a go
Check: identification and proof
4 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.