I'm just thinking about the passcode to unlock the iPhone. You have to retype the passcode regularly. Winter is coming - so wearing touch-gloves are fine for using the iPhone. To unlock the iPhone, Touch ID doesn't work with gloves, so you have to type the passcode again. Some other situations e.g. you got sweaty fingers, Touch ID doesn't work, passcode again.

I guess the passcode is part of the encryption. So I believe you should use a strong passcode instead of 4 easy digits. Besides the fact that passcode can always be used to unlock the phone, it's obvious you should use a strong passcode.

I couldn't find a lot of information about the passcode on the Internet. So I'd like to ask here. Does anyone know more about it? Are my guesses correct, or does it simply make no change to use a less strong passcode?

Update: My passcode is probably pretty strong. So typing the passcode is hardscrable for me.


A strong passcode is harder to brute-force. The code itself it not used directly as an encryption key but rather used as an input to derive a real key from. So regarding the crypto behind the scenes, it doesn’t make much of a difference, but mostly works against attacks from the interface.

  • Makes sense. Well, basically I'm more into securtiy then the casual guy, but often I'm really stressed when I have to type the passcode. Thanks. – MWe Oct 30 '18 at 15:18
  • You will probably benefit from a slightly longer numerical code, as brute forcing gets exponentially slower. So 6 or 8 for example. – John Keates Oct 30 '18 at 15:33
  • Currently I'm havin 20 characters alphanumerical + special characters. I guess I have to find a compromise between security and usability. – MWe Oct 31 '18 at 6:49
  • I think it helps to consider your threat model; maybe all you need to defend against is someone looking at your screen or someone trying your birthdate as a code. It’s unlikely that a threat is thwarted with your current code that would not be defended against with a 10- or 8-position code. – John Keates Oct 31 '18 at 10:16

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