A second gate (2FA) · 跟马丁学编程

A password + a code from the phone. Even if the password leaks, the account does not.

Two doors

A password is the first gate. A second gate (2FA, two-step verification) also wants a code from the phone or from an app. Whoever steals only the password does not get inside.

Imagine the entrance to school. The password is a key. The second gate is a porter who asks for a number from a scrap of paper that only you have. The key can be copied from a leak. The scrap is different that day. That is why it holds.

Switch it on for:

a school account (if school can do it — often school switches it on)
a parent’s main email, where password resets land
Drive, where notebooks hang
Apple ID / Google account, which the phone signs in with

A game with five levels can wait. First the doors school and photos flow through. Then the rest, if there is time.

Backup codes (a set of 一次性 numbers) belong with a parent, in the vault — not in chat, not in photos, not on the desktop as codes.txt. If the phone falls into the toilet, those codes are a spare key. An adult watches them.

⚠️

If someone calls “say the code that just arrived”, it is a scam. Never read a code into the handset. Not even to “support” of a game. Not even to “Microsoft”. Not even to “Google”. Not even to “school IT” that calls from an unknown number. Not even to a friend who is “just checking that it arrives”. A real service does not want a code into the phone. A code is a key. A key is not read to a stranger’s voice.

How to switch it on (with a parent)

You click. A parent watches. You do not read the email password to a sibling across the kitchen. The school method a teacher says has priority over this how-to.

With a parent, open the account that actually watches life: Google / school Workspace / Apple.
Google: browser → Google 账户 → Security → 2-Step Verification. On the phone: Settings → Google → Manage your Google 账户 → Security.

iPhone (Apple ID): Settings → [your name] → Sign-In & Security → Two-Factor Authentication. If it is on, leave it. Do not switch it off “so it is more comfortable”.

学校: an admin often switches it on. Do not go around it. It is not a punishment. It is a lock on notebooks.
Switch it on. A parent’s phone or the school method a teacher says. An app with codes (a manager / the official account app) is fine. There is no need to “break” anything or hunt shortcuts.
Print backup codes or save them in a password manager a parent watches. Not into 备注s named codes. Not into a photo of a scrap. Not into chat “so I have it”.

If the account offers a “trusted device”, that is this phone a parent already knows. Do not save a stranger computer in a library as trusted. After work, sign out.

If a code does not arrive, do not call the first number from an SMS. Wait. Try the network. Ask a parent. 学校 has a method a teacher knows. Hunting “how to go around it when the code will not come” does not belong here. The second gate should stay standing. A backup code with a parent is that plan B. Not switching the gate off.

What to do when a code arrives

An SMS or a notification arrived. You were just signing in. Use it with yourself on that page. Done.

A code arrived and you were not signing in. Someone is trying the door. Do not click a link in the message. Tell a parent: a code arrived and I was not signing in. The password may change. Do not read the code to anyone. Even if they call “we are school, we are verifying the account, or we will block it”. Rush + a code = a scam. You call school, with a number from Bakaláři, not from that SMS.

A friend writes “send the code, I am in your account, I need it”. No. An account is not lent. A code is not lent. From the chapter about sharing accounts it holds twice over.

What to say out loud

To a parent:

“I want to switch on a second gate on the mail school comes to. Will you sit next to me? You take the backup codes. I will not photograph them. And if someone calls me about a code, I will not read it. Even if they sound like a bank.”

To a sibling:

“If six numbers arrive and someone calls that they are from a game, hang up. A code is a key. A key is not read into the phone. Tell mum they called.”

To grandma:

“If a code arrives on the mobile and at the same time they call that they should hear it, it is a scam. Hang up. Tell us. A bank does not want that.”

To an operator / “support” from an unknown number:

“I do not say codes. I will call myself on the number from the account.” Then hang up. Find the number with a parent, not in the message that just arrived.

💡

A second gate is not for going around when you forget the phone. For that there are backup codes with a parent. If the phone is not there, you go to a parent. You do not hunt a how-to for switching the gate off. Switching it off “for a while” lots of scams can do. Leave it on.

Phone audit

Into the audit write: 2FA yes / school deals with it / not yet — which account. One line. Into family rules a sentence: We do not read a code from the phone to anyone. Not into the handset. Not to “support”.

Do not touch a school account if a teacher said they will switch it on. Write school deals with it. That is 完成.

Now you 💪

At least one important account has a second gate, or you know school will switch it on. Write into the audit: 2FA yes / school deals with it / not yet.

Practise with a parent the sentence: I do not read a code. So a sibling hears it too. A scam calls when calm is gone. The sentence has to be 完成 in advance.

✅

Check: You know what a code from the phone is for. You know it is not said into the handset. Backup codes are not in chat. They are with a parent.

What to take from this lesson

A password + a code. Even if the password leaks, the account does not.
Backup codes with a parent. Not on the desktop, not into photos.
Do not read an SMS code or an app code to anyone. A real service does not want it into the phone.
iPhone: Settings → [name] → Sign-In & Security. Google: 账户 → Security → 2-Step Verification.