Whether your smartphone is white, black or gold, it’s now about 30 times more valuable per ounce than a block of solid silver – and almost as easy to convert discreetly into cash. Is it any wonder that more than 10,000 mobile phones are now stolen in London every month?
The issue has become so serious that London mayor Boris Johnson has publicly questioned whether it is “beyond the wit of tech wizards to stop phone theft”. While this may not be the case, the question remains of how the industry can begin to tackle the smartphone theft issue.
The car stereo theft epidemic of the 1990s offers some lessons: change the value, or the ease with which thieves can liquidate that value, and make the stolen phone easier to recover and riskier to handle.
As a hacker, I solve problems with technology. Often that means reshaping the technology I work with, endowing it with new capabilities to serve my needs, and it is this way of thinking that we need to tap into when looking to solve the problem of smartphone theft. By hacking smartphone technology we can enhance it with features that will defend users against theft and ensure that those who do steal devices are caught and prosecuted.
Many of us have recently heard or seen the term “kill switch” floating around in the media. The concept of a kill switch can be interpreted in several different technical ways, each of which has its own advantages and disadvantages, but all of which attack the economy of smartphone theft.
1. Activation locks
Activation locks rely on a design that forces a smartphone owner to register with the manufacturer’s servers in order to activate its features. These servers track who a phone belongs to and keep a record of its basic security settings, so every time a device gets wiped clean or is reinstalled, they can reinstate the security locks and ownership rights the next time it activates.
Overall this is a good approach, but it does have a couple of weaknesses. First, you only discover that a phone is “locked” when you get part way into the reactivation process as that is typically when a wiped device starts to talk to the appropriate servers again. As this is not something a person buying a second hand phone is likely to discover until long after the transaction, the thief still has plenty of opportunity to sell the stolen device.
2. Persistent security software
Some manufacturers have announced that anti-theft tracking software will be installed as part of the phone’s operating system, with the idea that even if the device is wiped, this tracking software will remain installed. By making security software more difficult for criminals to remove, we both protect users and make it easier for the stolen phones to be found, and therefore riskier to sell. However, while this kind implementation makes the software harder to remove, it is not impossible so this approach should be combined with other security features for maximum effect.
3. Software or hardware to remotely ‘brick’ a phone
In this case, a “self-destruct” capability is built into the phone. Once the phone is stolen, this feature is activated, rendering the phone useless, like a brick. Rather than Mission Impossible-style exploding phones, this kind of feature usually relies on microscopic fuses that are embedded in the processors or software that irretrievably scrambles the device firmware. A bricked phone is the most dramatic approach that people think of when someone mentions a kill switch – however, it is also the hardest approach to get right.
First, it’s very hard to break hardware in a way that can’t be repaired since the industry is getting better at fixing things all the time, even at a microscopic level. Secondly, it will be incredibly hard to adequately secure this type of feature, particularly given the ability to kill large numbers of phones in an area or even a whole country.
Looking for a holistic solution
There is never going to be a single silver bullet that stops smartphone crime. The most effective approach to a kill switch will utilise a number of locking, disabling and tracking technologies in combination so that their strengths are magnified and their weaknesses mitigated.
The ideal approach will ensure that every time a device is wiped or reinstalled, it automatically authenticates with manufacturer or operator servers to re-establish the correct security software and security settings. Once reactivated, this software protects the device while advertising its true ownership, killing the opportunity for the thief to cash in on his crime. Meanwhile the device should silently begin to call for help by transmitting its location to the authorities even after the SIM card has been removed.
A robust, holistic approach such as this would represent a direct attack against the economy of smartphone theft. Instead of being a valuable commodity, a stolen smartphone would become a liability for whoever handles it: a digital whistleblower more likely to get a thief arrested than compensated.
Marc Rogers is principal security researcher for Lookout
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