Hackers may successfully unlock an iPhone in as soon as three to seven days, according to a representative of one effort that aims to unlock Apple's new handset.

"We believe it will be easy. We are privately aware many of the iPhone engineers came from other handset manufacturers, and we understand their design techniques fairly well," said gj, speaking in an interview conducted using IRC (Internet Relay Chat). He requested that his real name not be used.

"Easy to us means inside one week," he said, offering an estimate of three to seven days.

Unlocking the iPhone means users will be able to use the handset with other service providers, not just AT&T, which has an exclusive deal to sell the phone in the U.S.

By Tuesday night, U.S. time, hackers succeeded in cracking the iPhone's activation process, a minor step towards unlocking the iPhone but a significant technical challenge.

The activation process uses a software token that is sent from the phone via iTunes to Apple, which signs the token and returns it to the phone. When that process is completed, iTunes tells the phone to activate.

Hackers developed tools for both Windows and MacOS that allow users to activate their phones without iTunes. But users will have to use a token from an activated iPhone, which can be used to activate multiple phones. The hackers are not providing a token with the tools.

"If you don't have a known token (which does contain identifying information) you won't be able to use the tool," gj said.

At least one other hacker found a way to activate the iPhone without using iTunes. Jon Lech Johansen -- better known as DVD Jon, a hacker who helped develop the DeCSS tool for decrypting DVDs -- released a tool that can activate the iPhone without iTunes on his blog.

"The iPhone does not have phone capability, but the iPod and Wi-Fi work," Johansen wrote.

Cracking the activation process brings hackers one step closer to their goal of unlocking the iPhone. The phone requires iTunes to activate functions such as its camera and music player. But the process also requires signing up for a two-year data plan with AT&T.

"Activating the phone really just makes the device more 'usable' for those who want to use it as a Wi-Fi device, for instance," gj said.

With the activation process cracked hackers turned their focus to unlocking the iPhone, a challenge that is expected to be easier than cracking the activation process.

"Unlocking is a function of the radio and the radio's interaction with the SIM (Subscriber Identity Module) logic, and these are mostly standards based," gj said.

A rumored software update for the iPhone, expected to be released on July 5, could undo some of the progress hackers made towards unlocking the phone. "If Apple releases an update on July 5th that includes 'fixes' for our efforts so far, it will be a setback," gj said. "I don't know if it will be a permanent one."

Hackers working together to unlock the iPhone don't belong to a specific group, and don't plan to claim credit for their work, gj said. "We just want to see the hardware freed. We accept that others will exploit those works but hopefully it will be a lesson to Apple," he said.

"They're such a great company, it's a real shame for them to lock everything down like this. The design is top notch," he said. "They would win far more business by setting an example for the industry."