A postcard or a sealed letter
Imagine sending your bank details on a postcard. Anyone who handles it can read it. A sealed letter in a locked box is different. Only the person with the key can open it.
Data crossing the internet is like post. It passes through many hands. This lesson is about how to send it in the locked box.
By the end of this lesson
Note
I can explain how data is kept private when it is stored or sent.
Key words
| Word | What it means |
|---|---|
| Encryption | scrambling data so only the right people can read it |
| Key | the secret needed to lock or unlock encrypted data |
| VPN | a private, encrypted tunnel across a public network |
| HTTPS | the secure way a browser talks to a website |
| Digital certificate | a digital document that shows a website is genuine |
| Symmetric | the same key locks and unlocks the data |
| Asymmetric | a public key locks and a private key unlocks |
| Malware | software made to cause harm |
| Network | devices joined so they can share data |
The cells students fill in are left blank in this preview.
Starter: what you already know
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Starter: what you already know
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
Encryption locks data
Encryption scrambles data into a form nobody can read without the key. The scrambled data is useless to a thief. Only a person with the right key can turn it back.
You can encrypt a file, a whole folder or a whole disk. If a laptop with an encrypted disk is stolen, the thief still cannot read the files. Encryption also protects data sent over a network.
Two kinds of encryption
| Symmetric | Asymmetric | |
|---|---|---|
| Keys | One key does both jobs | Two keys: public and private |
| How it works | The same key locks and unlocks | The public key locks, the private key unlocks |
| Speed | Fast | Slower |
| Main problem | Sharing the key safely | Needs more work to set up |
| Often used | For large amounts of data | To share a key safely and to sign messages |
The cells students fill in are left blank in this preview.
Check
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Check
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.