Two-factor authentication (2FA): a second lock for your account

Two-factor authentication (2FA) is a way of signing in that requires a second proof besides your password: a one-time code from an authenticator app, a text message, a confirmation on your phone, a physical security key or biometrics.

2FA is a second lock whose key only you have

In plain words

A password is like a door key. If it is stolen, the burglar is inside. 2FA is like a second lock whose key only you have in your pocket - and it changes every 30 seconds. Even if your password leaks, without the "second key" the burglar stays outside.

How it works

You enter your password as usual.
The service asks for a second factor.
You enter a code from an authenticator app or text message, or confirm the sign-in on your phone.
The code is valid for only a few seconds and works once.
Without the second factor you cannot sign in, even with the right password.

A one-time code that changes every 30 seconds

Where you'll see it

2FA is available for Google, Apple ID, social networks, messaging apps (Telegram's cloud password, WhatsApp's PIN), banks, games (Steam, Epic Games) and email. Authenticator apps include Google Authenticator, Microsoft Authenticator, 2FAS, Authy and those built into password managers.

Does it matter when buying

It is essential for email, social media, banking and gaming accounts. My order of reliability: passkeys or a physical key > an authenticator app > confirmation on your phone > text message. A text message is better than nothing but vulnerable to SIM swapping.

Myths

Myth: 2FA is only for business people. Reality: Ordinary social media and gaming accounts are stolen most often - teenagers' too.
Myth: You can give your 2FA code to "support". Reality: Real support never asks for codes. It is always a scam.

FAQ

What if I lose the phone with my authenticator?

Use the backup codes you should save when setting up 2FA.

Are text messages reliable?

Better than nothing, but an authenticator app is more reliable.

What is a security key?

A physical USB/NFC device that confirms your sign-in - one of the most reliable methods.