Having an unlocked iPhone–without so much as a four-digit barrier between you and ... for a passcode—you can create a lengthy alphanumeric password or passphrase for your iPhone that will ...

Passcodes remain optional, and users can create a more complex alphanumeric password, but six digits ... the effort required to crack a four-digit passcode. Instead of 10,000 possible ...

Alpha-numeric passwords (that is, passwords with both letters and numbers) are inherently more secure. More possibilities means more security, right? Alas, the iPhone only supports 4-digit codes ...