GoalExplain multi-factor authentication as two proofs and give examples of a one-time code and a fingerprint.
New words
multi-factor authentication · using two or more proofs to open an accountone-time code · a short number that works once and then expiresfingerprint · the pattern on your fingertip, which is different for everyonefactor · one kind of proof
Explanation
At the school gate, a guard may ask for two things: your school card and your name on a list. One proof can be lost or copied, but two together are harder to fake. Online, this is multi-factor authentication. There are three kinds of proof. Something you know: a password or a PIN. Something you have: a phone that receives a one-time code, a short number that works once and then expires. Something you are: a fingerprint. With two proofs, a person who steals your password still cannot get in. Many accounts offer it. The disadvantages are small: it takes a few extra seconds, and you need your phone. Ask a grown-up to set it up.
Worked examples
A grown-up logs in with a password. The account then sends a code to her phone: 4 8 1 9. She types it in. The code works once and expires in a few minutes.
A stranger learns the password of Marwan’s father’s account. He cannot get in, because he does not have the phone that receives the one-time code.
A phone opens with a fingerprint. Only the owner’s finger fits. It is quick, but if the finger is wet or hurt, the phone may ask for a PIN instead.
Class activity
School gate game. Role play: one pupil is the guard and asks two things, ‘Say the secret word’ and ‘Show your school card’. On paper, draw the guard’s checklist with two boxes. Then sort six pretend proofs into know, have and are: a PIN, a phone, a fingerprint, a secret word, a school card, a face scan.
Practice
1
What are the three kinds of proof?
Something you know, something you have, something you are.
2
What is a one-time code?
A short number that works once and then expires.
3
Why does a second proof protect the account if someone steals the password?
The thief still needs your phone or fingerprint.
4
Which kind of proof is a fingerprint: know, have or are?
