The only downside I can see with Applepay is someone finding out your 4 digit pass, which can be circumvented by just watching someone type it in. Once in, a thief can add their fingerprint to the phone and use their own fingerprint for transactions if passbook already had cards stored, correct?
Well, if you are using TouchID, in theory you are very rarely entering your passcode. Apple states explicitly that TouchID is designed to:
1. Reduce the amount of times you have to enter the passcode
2. Encourage you to eliminate the delay before the passcode is required that many people enagaged because they hated entering passcodes
3. Encourage you to use longer passcodes
You'll notice that there is no delay that you can set before TouchID is active - it is always active as soon as the screen is turned off.
So a potential thief won't have many opportunities to figure out your pin code, even if you stick with a 4-digit code. Further, they wouldn't need to enter a fingerprint; the passcode can always be used to authorize a payment; after 5 invalid fingerprint scans it is required.
However, they also have to have your phone... Which, of course, you will be de-authorizing as soon as it is lost/stolen. You could either disable it in Find My iPhone or disable the card by calling the issuer the same as you would for a physical card. Further, Find My iPhone will target the criminal's location inside a store where it is likely that security cameras are capturing the attempted use of your phone for posterity.
But seriously, how many people are EVER held up for their credit cards? Cash, yes - but single credit cards are useless unless you intend to kill the victim before they can make the call to the issuer.
I think entering Passbook and fingerprint should use a more secure and longer string and make that mandatory and not allow 4 digit pass for those two areas specifically.
People's 4 digit code is inherently weak placing more valuable info and permissions at risk.
I can't really argue against this, but since there are protections in place (escalating lockouts and the option to secure wipe the phone on too many invalid passcode attempts), the risk is somewhat balanced against the potential for non-savvy users to forget their passcode. Savvy ones can always use long passcodes. I will say, however, that it would be nice if you got a dialog box explaining why you would want a longer passcode and offering to bring you to the right place in Settings to configure it.
Think about it. If the enclave is really as secure as it states, then the thief would have no worry about including their fingerprint cause the authorities can't get in their right? I mean fingerprint data is never passed along in a transaction.
Fingerprints themselves are never actually stored in the Secure Enclave. To simplify, the points of your fingerprint are described in terms of data points, which are what is stored. They cannot (to my knowledge) be reverse engineered into a graphical fingerprint. Call it a one-way hash function.
