It took 17-year-old George Hotz two months of work to undermine AT&T;'s investment.
Hotz, a resident of Glen Rock, N.J., published detailed instructions online this week that he says will let iPhone owners abandon AT&T; Inc.'s wireless service and use their phones on some competing cellular networks.
Hotz's method, which requires a soldering gun, a steady hand and a set of obscure software tools, is one of several techniques that have emerged over the past week to break the technological locks confining the iPhone to AT&T;'s network.
"This was about opening up the device for everyone," Hotz said in an interview over his iPhone, which he was using on the network of T-Mobile, a rival to AT&T.;
Carriers such as Verizon, AT&T; and Sprint seek to keep their customers in two ways. They force them to sign multiyear contracts, which are expensive to break. And the carriers put complex technological locks on phones to ensure that they run only on a given carrier's wireless network. Without the locks, the phones could be used on rival networks that use the same underlying technology.
People who work on unlocking cell phones say they think those technical locks unfairly restrict customer choice. They want to give mobile phone users the flexibility to take their phones with them overseas or to transfer them to other networks once their service contract expires.
Hotz says it took him about 500 hours to unlock two iPhone units. He put one of them up for sale on eBay, and by late yesterday, bids on the phone, which sells for $499 at an Apple store, had reached many thousands of dollars.
His technique is probably not accessible to regular people. But Hotz described it in detail on his Web site in the hopes that others can simplify the procedure.
Neither Apple nor AT&T; would comment on Hotz's handiwork, or on another unlocking technique revealed yesterday by an anonymous group calling themselves iPhoneSimFree.
Members of that group demonstrated their technique to a writer of the gadget site Engadget. They said they had developed a way to unlock iPhones with a software update, and without any changes to the device itself.
IPhone owners can presumably run that software and then insert another carrier's SIM card - the small card inside phones that run on GSM networks, which store information about the subscriber. They would still have to pay monthly fees to AT&T;, however, until their contracts expire.
A writer for Engadget verified that the iPhoneSimFree technique worked. Only AT&T;'s visual voice-mail system, which allows users to retrieve voice mail in whatever order they choose, ceased to work when an iPhone was removed from the AT&T; system.
In an e-mail interview with members of the six-man iPhoneSimFree team, the group said that it had been working on unlocking the iPhone since June and that it planned to start selling its software to parties that want to unlock large groups of iPhones. The members did not disclose what they intended to charge, and they declined to reveal their identities.
'A bit paranoid'
"We're a bit paranoid about privacy because we don't know how things are going to evolve," said one group member, who identified himself only as Jim. His caution stems from the murky legal status around the unlocking of cell phones.
Last fall, the Librarian of Congress issued an exemption to the Digital Millennium Copyright Act, ruling that people can legally unlock their mobile phones. But the ruling does not apply to people, such as Hotz and the iPhoneSimFree group, who distribute the actual unlocking tools.
Apple and AT&T; could conceivably sue them under the copyright act. They could also argue that the phone hackers are interfering with their business relationship with customers.
Apple might also seek to block the unlocking tools with its regular software updates to the iPhone. Hotz says he believes his unlocking process is immune to such changes, because he is making a change to the device's read-only memory, which cannot be fixed with a software patch.
One other approach to unlocking the iPhone has been making waves.
Two weeks ago, a company called Bladox, based in the Czech Republic, began selling an $80 device called a Turbo SIM. The thumbnail-size card, attached to another carrier's SIM card and inserted into an iPhone, works by convincing the iPhone that it is still running on the AT&T; network even when it is not.