NewsBeat

May/June 2017 NewsBeat 19 PHOTO OF AN OLD DATSUN AD BY JOHN LLOYD USED UNDER A CREATIVE COMMONS LICENSE. Why use iOS? The fact of the matter is that when it comes to addressing these remaining issues, Apple phone operating systems (on iPhones and iPads) simply have a better track record. Since Apple is the only manufacturer of iOS devices, there is no "middleman" when it comes to monitoring for iOS issues and deploying iOS security updates. This means that the buck stops at Apple — rather than with some third-party equipment manufacturer. Indeed, Apple routinely patches its operating systems and pushes the patches to all supported users — sometimes within hours of learning of a vulnerability (something that is realiatively tare at this point in any case). Of course, to be fair: Google has also become fairly decent at supporting its own Android devices. However, to get assurance from this process you need to be running a relatively brand new device and it needs to be manufactured by Google. Otherwise you're liable to be several days or weeks behind the time when a security issue is discovered and patched — if you ever get it. And Google still does not support all of the features Apple does, including in-memory code signing and strong file encrypton. Apple also seems to do a relatively decent job at curating its App Store, at least as compared to Google. And because those apps support a more modern base of phones, they tend to have access to better security features, whereas Android apps more routinely get caught doing dumb stuff for backwards compatibility reasons. Finally, every recent Apple device (starting with the iPhone 5S and up) also includes a specialized chip known as a "Secure Enclave Processor", this hardened processor assists in securing the boot chain — ensuring that nobody can tamper with your operating system. It can also protect sensitive values like your passwords, ensuring that only a password or fingerprint can access them. A few Android phones also offer similar features as well. However, it's unclear hot well these are implemented in contrast to the Apple's SEP. It's not a bet I would choose to take. So does using iOS mean I'm perfectly safe? Of course not. Unfortunately, computer security today is about resisting attacks. We still don't quite know how to prevent them altogether. Indeed, well-funded attackers like governments are still capable of compromising your iOS device (and your Android, and your PC or Mac). Literally the only question is how much they'll have to spend doing it. Here's one data point. Last year a human rights activist in the UAE was targeteted via a powerful zero day exploit, likely by his government. However, he was careful. Instead of clicking the link he was sent, the activist sent it to the engineers at Citizenlab who reverse-engineered the exploit. The resulting 35-page technical report by Lookout Security and Citizenlab is a thing of terrifying beauty: it describes a chain of no less than three previously unpublished software exploits, which together would have led to the complete compromise of the victim's iPhone. But such compromises don't come cheap. It's easy to see this kind of attack costing a million dollars or more. This is probably orders of magnitude more than it would cost to compromise the typical desktop user. That's important. Not perfect, but important. You're telling me I have to give up my desktop machine? Not at all. Or rather, while I'd love to tell you that, I understand this may not be realistic for most users. All I am telling you to do is to be thoughtful. If you're working on something sensitive, consider moving the majority of that work (and communications) to a secure device until you're ready to share it. This may be a bit of a hassle, but it doesn't have to be your whole life. And since most of us already carry some sort of phone or tablet in addition to our regular work computer, hopefully this won't require too much of a change in your life. You can still use your normal computer just fine, as long as you're aware of the relative risks. That's all I'm trying to accomplish with this post. In conclusion I expect that many technical people will find this post objectionable, largely because they assume that with their expertise and care they can make a desktop operating system work perfectly safely. And maybe they can! But that's not who this post is addressed to. And of course, this post still only scratches the surface of the problem. There's still the problem of selecting the right applications for secure messaging (e.g., Signal and WhatsApp) and finding a good secure application for notetaking and document collaboration and so on. But hopefully this post at least starts the discussion. MATTHEW GREEN — I'm a cryptographer and professor at Johns Hopkins University. I've designed and analyzed cryptographic systems used in wireless networks, payment systems and digital content protection platforms. In my research I look at the various ways cryptography can be used to promote user privacy.

• Cover