This chapter is from the book
This chapter is from the book
This chapter is from the book
Encrypting Your Device
To protect your device against unauthorized access if you lose it, you can encrypt its contents. Encryption deliberately scrambles the content using an encryption key, leaving the content unreadable without the key to decrypt it.
NOTE
Encryption can take an hour or more, depending on the amount of data your device contains and its processor speed; and if encryption fails to complete, your data may get corrupted. So Android ensures enough power is available by making the encryption controls unavailable unless the device’s battery is fully charged and the device is connected to a power supply.
For the encryption to work, you must set a lock screen PIN or password to prevent others from unlocking your device. If you’ve already set a PIN or password, you’re good to go; if not, go back to the section “Setting Up Locking on Your Device,” earlier in this chapter, and set one or the other.
CAUTION
Android’s encryption is strong enough to prevent civilian attackers from unencrypting it. However, you should assume that law-enforcement agencies and government security agencies have tools powerful enough to crack the encryption without breaking a serious sweat.
Encrypting the Data on Your Device
Here’s how to encrypt your device:
Fully charge the battery, and leave the device connected to power.
Open the Settings app.
Tap the Security button in the Personal section to display the Security screen.
NOTEDepending on your device, the encryption settings may be in a different location. If you can’t find them, search for “encrypt.”
Tap the Encrypt Phone button or the Encrypt Tablet button (whichever one appears). The Encrypt Phone screen or the Encrypt Tablet screen appears. (Some devices have the Encrypt Device button and Encrypt Device screen instead.)
Read the information and then tap the Encrypt Phone button or the Encrypt Tablet button. The Confirm Your PIN screen or Confirm Your Password screen appears.
NOTEIf your device doesn’t have a PIN or password set, the No Lock Screen PIN or Password dialog box opens, telling you that you need to set a PIN or password. Turn back to the section “Setting Up Locking on Your Device,” earlier in this chapter, and return when you have set a PIN or password.
Type your PIN or password.
Tap the Continue button. The Encrypt screen appears, warning you that encryption is irreversible and that your device will restart several times during the encryption process.
Tap the Encrypt Phone button or the Encrypt Tablet button. Android starts the encryption process. You’ll see the Encrypting screen with a progress readout as it works.
When the Type Password to Decrypt Storage prompt appears, type your PIN or password and tap the Done button on the keyboard. Android then decrypts your data, the lock screen appears, and you can type your PIN or password (again) to unlock the device as usual.
NOTE
If you have a PIN rather than a password, don’t worry that the Type Password to Decrypt Storage prompt asks for a password. Type in your PIN, and all will be well.
TIP
If encryption fails on a tablet that has multiple user accounts set up, try updating to the latest version of Android before encrypting the tablet.
Decrypting the Data on Your Device
The only way to decrypt the data on your device is to perform a factory data reset. This move wipes all your apps and data off your device and restores it to its original settings.
CAUTION
Back up your device’s data to your computer or to an online account—or, better, to both—before performing a factory data reset.
TIP
You may want to perform a factory data reset before selling your phone or tablet or giving it to someone else.
Here’s how to perform a factory data reset:
Open the Settings app.
Tap the Backup & Reset button in the Personal section to display the Backup & Reset screen.
Tap the Factory Data Reset button. The Factory Data Reset screen appears. (See the left screen in Figure 3.11.)
FIGURE 3.11 On the Factory Data Reset screen (left), tap the Reset Phone button or Reset Tablet button. On the Reset screen (right), tap the Erase Everything button.
The Confirm Your PIN screen or Confirm Your Password screen appears.
Type your PIN or password.
Tap the Continue button. The Reset screen appears, displaying a final, excited warning. (See the right screen in Figure 3.11.)
Tap the Erase Everything button. The Power Off dialog box opens for a few seconds. The device then shuts down and restarts. The Erasing screen appears while Android erases the data.
)
Android then resets the operating system to factory defaults and displays the Welcome screen. You can then set up your device again as you did when you first got it.
TIP
The quickest and easiest way to get your device up and running again is to restore data from your Google account to it. Tap the Yes button on the Got Google screen, and then type your email address and password on the Sign In screen. When the Google Services screen appears, check the box called “Back Up Your Data to a Google Account. Restore Previous Backups to This Device.”
Performing a Hard Reset
In addition to the factory data reset explained in the previous section, there’s another type of reset called a hard reset. A hard reset is a move you typically perform when your device won’t start correctly; for example, it crashes while loading Android.
Here’s an example of how to perform a hard reset. These instructions are specifically for the Nexus 5X running stock Marshmallow.
Power down your phone or tablet. Press and hold the Power button until the Power dialog box opens, and then tap the Power Off button in the dialog box that opens.
NOTEIf the Power dialog box doesn’t appear because your device is frozen, keep holding down the Power button until the device turns off.
Hold down the Volume Up button, the Volume Down button, and the Power button for several seconds. Your device turns on and displays a picture of an Android lying on its back with its cover open for maintenance. Release the buttons.
TIPDifferent devices use different combinations of hardware buttons to perform a hard reset. If the combination given here doesn’t work for your device, search online for the device’s name and recovery buttons.
Press the Volume Up button or the Volume Down button one or more times until the Recovery Mode button appears at the top of the screen.
Press the Power button to give the Recovery Mode command. Your device restarts and displays another screen showing an Android lying on its back, cover open for maintenance, a red triangle with an exclamation point, and the message “No Command.”
Press and hold the Power button and then press the Volume Up button. The Android Recovery screen appears.
Press the Volume Up button or the Volume Down button to select the Wipe Data/Factory Reset command on the menu.
Press the Power button to give the command. A confirmation screen appears because this is a drastic move.
Press the Volume Up button or the Volume Down button to select the Yes – Erase All User Data command.
Press the Power button to give the command. Android erases the data, restarts, and displays the Welcome screen. You can then set up the device from scratch.