September 25, 2017

iPhone Unlocking Secret Revealed

The iPhone unlocking story took its next logical turn this week, with the release of a free iPhone unlocking program. Previously, unlocking required buying a commercial program or following a scary sequence of documented hardware and software tweaks.

How this happened is interesting in itself. (Caveat: This is based on the stories I’m hearing; I haven’t confirmed it all myself.) The biggest technical barrier to a software-only unlock procedure was figuring out the unlocking program, once installed on the iPhone, could modify the machine’s innermost configuration information – something that Apple’s iPhone operating system software was trying to prevent. A company called iPhoneSimFree figured out a way to do this, and used it to develop easy-to-use iPhone unlocking software, which they started selling.

Somebody bought a copy of the iPhoneSimFree software and reverse engineered it, to figure out how it could get at the iPhone’s internal configuration. The trick, once discovered, was easy to replicate, which eliminated the last remaining barrier to the development and release of free iPhone unlocking software.

It’s a commonplace in computer security that physical control over a device can almost always be leveraged to control it. (This iceberg has sunk many DRM Titanics.) This principle was the basis for iPhoneSimFree’s business model – helping users control their iPhones – but it boomeranged on them when a reverse engineer applied the same principle to iPhoneSimFree’s own product. Once the secret was out, anyone could make iPhone unlocking software, and the price of that software would inevitably be driven down to its marginal cost of zero.

Intellectual property law had little to offer iPhoneSimFree. The trick turned out to be a fact about how Apple’s software worked – not copyrightable by iPhoneSimFree, and not patentable in practice. Trade secret law didn’t help either, because trade secrets are not shielded against reverse engineering (for good reason). They could have attached a license agreement to their product, making customers promise not to reverse engineer their product, but that would not be effective either. And it might not have been the smartest thing to rely on, given that their own product was surely based on reverse engineering of the iPhone.

Now that the unlocking software is out, the ball is in Apple’s court. Will they try to cram the toothpaste back into the tube? Will they object publicly but accept that the iPhone unlocking battle is essentially over? Will they try to play another round, by modifying the iPhone software? Apple tends to be clever about these things, so their strategy, whatever it is, will have something to teach us.

Intellectual Property and Magicians

Jacob Loshin has an interesting draft paper on intellectual property among magicians. Stage magic is a form of technology, relying on both apparatus and technique to mislead the audience about what is really happening. As in any other technical field, innovations are valuable, and practitioners look for ways to cash in on their inventions. They do this, according to Loshin, without much use of intellectual property law.

This makes magic, like cuisine and clothing design, a thriving field that operates despite a lack of strong legal protection for innovation. Recently legal scholars have started looking harder at such fields, hoping to find mechanisms that can support innovation without the cost and complexity of conventional intellectual property law, and wondering how broadly those alternative mechanisms might be applied.

What makes magic unusual is that practitioners rarely rely on intellectual property law even though magic tricks are protectable by patent and as trade secrets. Patent protection should be obvious: patents cover novel mechanisms and methods, which most magic technologies are. Some classic tricks, such as the saw-a-person-in-half trick, have been patented. Trade secret protection should be obvious too: how to do a particular trick is valuable business information whose secrecy can be protected by the inventor. (The audience sees the trick done, but they don’t really see the secret of the trick.)

Yet Loshin, and apparently most magicians, think that patent and trade secret are a poor fit. There are basically three reasons for this. First, part of the value of a trick is that the audience can’t figure out how it’s done; but a patent must explain the details of the invention. Second, tricks are subject to “reverse engineering” by rival magicians who watch the trick done, repeatedly, from different parts of the audience, then do experiments to try to replicate it; and of course trade secrets are not protected against reverse engineering. Third, there’s a sort of guild mentality among magicians, holding that knowledge can be shared within the profession but must not be shared with the public. This guild mentality can’t easily be implemented within current law – a trade secret must be carefully protected, and so cannot be passed around casually within a loosely defined “community”.

The result is that the guild protects its secrets through social norms. You’re accepted into the guild by demonstrating technical prowess and following the guild’s norms over time; and you’ll be excommunicated if you violate the norms, for example by making a tell-all TV special about how popular tricks are done. (There’s an exception for casual magic tricks of the sort kids do.) The system operates informally but effectively.

As a policy guy, I have to ask whether this system is good for society as a whole. I can understand why those inside the profession would want to limit access to information – why help potential competitors? But does it really benefit society as a whole to have some unelected group deciding who gets access to certain kinds of information, and doing this outside the normal channels that (at least in principle) balance the interests of society against those of inventors? It’s not an easy question.

(To be clear, asking whether something is good or bad for society is not the same as asking whether government should regulate it. A case for regulation would require, at least, that the regulated behavior be bad for society and that there be a practically beneficial way for government to intervene.)

The best argument that magicians’ guild secrecy benefits the public is that tricks are more valuable to the public if the public doesn’t know how they are done. This is almost never the case for other technologies – knowing how your iPod works doesn’t make it less valuable to you – but it just might be true for magic, given that it exists for entertainment and you might enjoy it more if you don’t know how it’s done.

But I have my doubts that publishing information about tricks actually makes them less entertaining. Goldin’s patent on the saw-a-person-in-half trick – which explains pretty clearly how to do the trick – was issued in 1923, but the trick is still a staple today. In theory, anybody can read Goldin’s patent whenever they want; but in practice hardly anybody has read it, and we all enjoy the trick despite suspecting how it’s probably done. And do we really need to read Gaughan’s patent to know how a “levitating” magician stays up in the air? Gaughan’s cleverness is all about how to keep the audience from seeing the evidence of how it’s done.

One effect of the guild’s secrecy is that the public rarely learns who the great innovators are. We know who puts on a good show, but we rarely know who invented the tricks. The great innovators may be venerated within the profession, but they’re unknown to the public. One has to wonder whether the field would move faster, and be more innovative and entertaining, if it were more open.

DRM for Chargers: Possibly Good for Users

Apple has filed a patent application on a technology for tethering rechargeable devices (like iPods) to particular chargers. The idea is that the device will only allow its batteries to be recharged if it is connected to an authorized charger.

Whether this is good for consumers depends on how a device comes to be authorized. If “authorized” just means “sold or licensed by Apple” then consumers won’t benefit – the only effect will be to give Apple control of the aftermarket for replacement chargers.

But if the iPod’s owner decides which chargers are authorized, then this might be a useful anti-theft measure – there’s little point in stealing an iPod if you won’t be able to recharge it.

How might this work? One possibility is that when the device is plugged in to a charger it hasn’t seen before, it makes a noise and prompts the user to enter a password on the iPod’s screen. If the correct password is entered, the device will allow itself to be recharged by that charger in the future. The device will become associated with a group of chargers over time.

Another possibility, mentioned in the patent, is that there could be a central registry of stolen iPods. When you synched your iPod with your computer, the computer would get a digitally signed statement from the registry, saying that your iPod was not listed as stolen. The computer would pass that signed statement on to the iPod. If the iPod went too long without seeing such a statement, it would demand that the user do a synch, or enter a password, before it would allow itself to be recharged.

How can we tell whether a DRM scheme like this is good for users. One sure-fire test is whether the user has the option of turning the scheme off. You don’t want a thief to be able to disable the scheme on a stolen iPod, but it’s safe to let the user disable the anti-theft feature the first time she syncs her new iPod, or later by entering a password.

We don’t know yet whether Apple will do this. But reading the patent, it looks to me like Apple has thought carefully about the legitimate anti-theft uses of this technology. That’s a good sign.