The free café Wi-Fi
Jo opens her work laptop in a café and joins the free Wi-Fi. It has no password.
Anybody in the café can see the traffic that is not locked. Anybody can also set up a fake copy of the Wi-Fi with the same name.
Four controls protect Jo and the company: Wi-Fi security, device sign-in, a second proof and a clean sign-out.
Key words
| Word | What it means |
|---|---|
| Wi-Fi | Wireless network access for devices. |
| WPA2 | A common way to lock a Wi-Fi network. It encrypts the traffic. |
| WPA3 | The newer way to lock Wi-Fi. It is harder to crack and protects each user better. |
| WEP | An old Wi-Fi lock that is broken and must not be used. |
| End-to-end security | Protection that stays on the data all the way from sender to receiver. |
| MFA | Multi-factor authentication: two or more different kinds of proof to sign in. |
| SLO | Single logout: signing out in one place signs you out of every linked system. |
| Authentication | Proving that you are who you say you are. |
| Encryption | Scrambling data so only a person with the right key can read it. |
| Network | Computers and devices linked so they can share data. |
The cells students fill in are left blank in this preview.
By the end of this lesson
Note
I can choose the right Wi-Fi security, say how a device is protected by sign-in, and explain MFA and single logout.
Starter: last lesson
Have a go
Starter: last lesson
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
Cycle 1: wireless security
Radio waves go through walls. So Wi-Fi traffic must be locked.
WPA2 locks the traffic with a shared password. It is still common. A weak password is its main risk.
WPA3 is newer and better. Each device gets its own protection, and an attacker cannot copy the traffic and guess the password later. Use it when the devices support it.
WEP is broken in minutes. Never use it.
Worked example: which Wi-Fi security?
| Choice | Safe to use? | Note |
|---|---|---|
| WPA3 | Yes, best choice | Use for new equipment |
| WPA2 with a long password | Yes, acceptable | Move to WPA3 when you can |
| WEP | No | Broken, replace the equipment |
| Open, no password | No for work | Anybody can listen |
The cells students fill in are left blank in this preview.
End-to-end security and monitoring access
Wi-Fi locking protects only the radio part, up to the access point. After that the data is on the wired network.
For end-to-end security, add another lock on top, such as TLS or a VPN. Then the data stays locked until it reaches the other end.
To monitor access, give staff their own logins to the Wi-Fi, not one shared password. Then the log shows who joined, and one person can be removed at once. Put guests on a separate network.
Check: Wi-Fi
Have a go
Check: Wi-Fi
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.