If you are using a passcode that is made of 6 numbers or worse just 4 numbers, then you may want to change based on the report earlier in the week which revealed that a 6-digit passcode can be cracked in 11 hours and the 4-digit passcode in just 6 and half minutes using a new and relatively cheap technology called GrayKey to unlock iPhones.
Matthew Green, an assistant professor and cryptographer at the Johns Hopkins Information Security Institute, advise was to use an alphanumeric passcode that isn’t susceptible to a dictionary attack and that is at least 7 characters long and has a mix of at least uppercase letters, lowercase letters, and numbers.
Here’s how to set an alphanumeric passcode on your iPhone and iPad:
- Launch the Settings app on your iPhone or iPad.
- Scroll down and tap on Touch ID and Passcode or Face ID and Passcode.
- Enter the passcode when prompted.
- Scroll down and tap Change Passcode.
- Enter the old passcode when promoted.
- Then tap Passcode Options.
- Tap Custom Alphanumeric Code.
- Enter the new alphanumeric passcode. As Professor Green recommends, use an alphanumeric passcode which is at least 7 characters long and has a mix of at least uppercase letters, lowercase letters, and numbers.
- Tap Next. You will be prompted to verify the new passcode. Enter the new alphanumeric passcode again.
If you’re using Face ID or Touch ID, then the alphanumeric passcode shouldn’t be very inconvenient as you will need to enter it only when you reboot your iPhone or iPad.
