The 2-step verification in Gmail prevent others without permission can access your Gmail account if they find out the password.
What is the 2-step verification?
To access an email account with a normal security system, simply enter Gmail address and Gmail password. But what happens if someone is Gmail password for the method that is? This is where itmakes sense the figure of the “2-step verification” that has introduced Gmail and it is very useful to prevent unwanted intrusions. The 2-step verification, as defined by Google, requires two factors: something you know (your password) and something you have in your possession , as a code sent to your phone. In this way, you need both to access. No use having only the password. It is something similar to what some banks offer online services, in addition to ask an identification code to request a key is a physical card you have. When you got into your account, you will see the following message:
Why you should enable 2-step verification?
The two-step verification prevents others from accessing without permission from the user’s account if they find out the password. The attacker, guessed or otherwise, steal your password, can not log without user verification codes, which can only get the user through their mobile phone.
How do I turn on 2-step verification?
Step 1. Login to your Google account in your web browser and then visit the Security settings for your Google account : https://www.google.com/settings/security/. You might have to enter the password once more to open the settings.
Step 2. In the section under Password & sign-in method, click on 2-Step Verification.
Step 3. If it is not already selected, click Verification Codes.
Step 4. Under Backup Options, click Add a phone number. This is an important step should you ever need access to your account and find yourself without your YubiKey. Note that we recommend that you have a second YubiKey for backup so that you can always access your accounts – similar to how you have an extra copy of your keys for your house and car.
Step 5. In the Add backup phone number dialog box, enter your phone number and specify how you want to receive codes (usually by SMS text message). If you want to verify that your backup method works, click Send Code, then click Save.
You also have backup codes that you can use to gain access to your account. This is an additional mechanism to use if you do not have access to your YubiKey or your phone. You might find it useful to copy these backup codes and put them in a safe place. To do this, click Show backup codes. A new browser window is opened so you can manage your backup codes. Click Print or Save to text file, to save your codes. In the future, if you notice you have used a few of your backup codes and you are worried about running out of them, you can return to this screen and click Generate new codes.
Step 6. Now you are ready to register your YubiKey as your 2-Step Verification device. Click Security Keys, and then click Manage.
Step 7. This is the really cool part! If your YubiKey is inserted, remove it. Now click Register, insert your U2F YubiKey, wait for it to blink, and tap the YubiKey button. Your YubiKey is now registered to your account as your default 2-Step Verification device!
Step 8. The screen now displays all devices that are registered to your account, so you can easily add another Security Key, or remove registered keys. (If you accidentally lose a YubiKey, come here and remove that YubiKey from your account. No one could log on to your account, though, because they would still need to know your password.)
How do I turn off 2-step verification?
The same process from step 1 to step 3 of 2-step verification turn on. In the section under Password & sign-in method, click Off 2-Step Verification.
What if I lose my phone?
In this case, the service offers the ability to add the phone number of a relative or friend. In an emergency, you can ask them to send a verification code to that number. It can be a number of mobile or fixed phone and not use it unless you ask.
After this tutorial, hope to help you secure your Gmail account more secure.