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Texas Instruments aims lawyers at calculator hackers

Is device modding a punishable offense?

Lawyers for Texas Instruments are taking aim at a group of calculator enthusiasts who posted the cryptographic keys used to modify the devices so they run custom-designed software.

Over the past few weeks, TI has sent webmasters letters invoking the DMCA, or US Digital Millennium Copyright Act (PDF), and demanding they remove the keys published in blog postings. The private keys are needed to sign operating systems before they work on a wide variety of calculator models designed by the Dallas-based electronics manufacturer.

Because TI generated the keys using extremely weak 512-bit ciphers, the hobbyists were able to crack the vast majority of them in a matter of weeks using an open-source project for distributed computing known as BOINC. The keys make it possible for them to write DIY versions of firmware that in some cases hasn't been updated in more than four years.

"Writing an operating system allows us to use the calculator in ways that are either very difficult or infeasible with TI's operating system," said Brandon Wilson, a 25-year-old programmer who's been writing his own calculator software for about a decade. "By writing our own, we can go about things our own way."

In late August, an attorney sent Wilson a letter warning that a posting on his website ran foul of TI's copyrights because it contained "information that bypasses TI's anti-circumvention technology" that could defeat encryption systems protecting the TI-83 Plus OS. Wilson quickly complied and removed the keys.

On Monday, the attorney struck again, this time against University of Washington student Duncan Smith, who had published the keys' raw materials on ticalc.org, a website dedicated to, well, TI calculators. Smith also took down the posting.

Neither hobbyist consulted with an attorney before caving in to the demands, and that may have been a mistake. According to two attorneys, it's not at all clear TI is using DMCA takedown provisions as Congress intended. What's more, modifications to calculators may be similar to unlocking cell phones, an activity the US Copyright Office has formally exempted from the DMCA.

"When websites publish these cracked keys, the websites aren't violating the copyright per se," said Eric Goldman a professor specializing in cyber law at Santa Clara University. Rather, "they might be violating provisions of the anti-circumvention rules under the copyright act."

While it's clear the DMCA requires websites to remove content that infringes copyright, courts have yet to weigh in on whether those provisions apply to material that makes it possible for others to defeat electronic locks protecting copyrighted works, he added.

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