The guest list and the ban list
A club has two lists. One list names who may come in. The other names who is banned.
Computers use the same two ideas. Add a list of who may do what, a safe test room and a tidy-up of settings. These are the technical controls in this lesson.
Key words
| Word | What it means | Example |
|---|---|---|
| Allowlist | A list of what is allowed. Everything else is blocked. | |
| Denylist | A list of what is blocked. Everything else is allowed. | |
| Access control list | A list of who may do what to a file, device or network. | ACL |
| Sandbox | A safe, sealed space to run a program so it cannot harm the rest of the computer. | |
| Device hardening | Removing what a device does not need, so there is less to attack. | |
| Certificate authority | A trusted body that issues digital certificates. The next lessons explain it. | |
| Permission | The right to read, change or run something. | |
| Default | The setting a device has when it is new. | |
| Network | Computers and devices joined together so they can share data. | |
| Router | A device that sends data between networks. | |
| Firewall | A filter that allows or blocks network traffic by rules. |
The cells students fill in are left blank in this preview.
By the end of this lesson
Note
I can explain what an allowlist, a denylist, an access control list, a sandbox and hardening do.
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: two lists
An allowlist is the strict one. Only what is on it may run or connect. A new program is blocked until somebody adds it.
A denylist is the loose one. Everything is allowed except what is on the list. It is easier to run. A new bad thing gets through until somebody adds it.
An access control list says who may do what. Routers, firewalls and file systems all use them.
Allowlist and denylist compared
| Allowlist | Denylist | |
|---|---|---|
| Default answer | Block | Allow |
| What is on the list | What is allowed | What is blocked |
| Safer for | A kiosk or server with few jobs | A busy open network |
| Risk | Staff cannot do a new job until it is added | A new bad thing is not on the list yet |
The cells students fill in are left blank in this preview.
Check: which list?
Have a go
Check: which list?
4 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.