Securing Siri on a Locked iPhone 4S

Although I haven’t had the chance to play with her myself (does that sound wrong?), Siri seems like an awesome addition to the iPhone. It’s worth pointing out, however, that it is still possible to use Siri when the iPhone is locked – presumably for convenient ease-of-use. Unfortunately this means that anyone with physical access to your phone can access information including contacts, calendar items, SMS/iMessages, and also make calls and send emails or messages from you.

[Update] There have been a whole bunch of people crying about how this is a major security flaw. Just to dispel some of the myth… this is not a security flaw, it’s a design decision that Apple made based on usability. Yes, it’s a default setting that may introduce some vulnerabilities, but then again there are still lots of people who run around without passcodes. To be honest I’m usually the first to secure the hell out of everything, but in this case I feel they made the right decision for two reasons. First, Siri is obviously less useful as a hands-free assistant if you need to unlock your phone every time; and secondly making it easier to use will help drive the adoption of Siri.

Luckily Apple thought of this on at least two levels. First, if you ask Siri to unlock your iPhone she’ll respectfully tell you that she “can’t unlock your phone for you”. Secondly – and this is the important one – it is possible to disable the use of Siri when the iPhone is locked. The option now lives in Settings > General > Passcode Lock, where you can set Siri to Off.

Needless to say (contrary to the screenshot), I recommend setting ‘Require Passcode’ to Immediately, turn Simple Passcode off so you can set a 5-or-more-digit PIN, set ‘Siri’ to off to prevent access when your  iPhone is locked, and turn on Erase Data after 10 failed passcode attempts.

Siri is great, but let’s not make it easy for someone to social-engineer her into betraying you. See my other post for more details on protecting your iPhone from loss and theft.

In other news… you can tell Siri to use a specific nickname when talking to you. It’s important to note, however, that the nickname will be put into your VCard. So be careful if you tell her to call you her pimp, and then send someone your contact details ;)