The Case of the Top Secret iPod
They didn’t actually work for the Department of Energy; they worked for a division of Bechtel, a large US defense contractor to the Department of Energy. They wanted to add some custom hardware to an iPod and record data from this custom hardware to the iPod’s disk in a way that couldn’t be easily detected. But it still had to look and work like a normal iPod.
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Finally, the iPod team developed on Windows computers. Apple didn’t have working ARM developer tools yet, because this was before the iPhone shipped. The iPod team used ARM developer tools from ARM Ltd, which ran only on Windows and Linux.
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We discussed the best way to hide the data they recorded. As a disk engineer, I suggested they make another partition on the disk to store their data. That way, even if someone plugged the modified iPod into a Mac or PC, iTunes would treat it as a normal iPod, and it would look like a normal iPod in the Mac Finder or Windows Explorer. They liked that, and a hidden partition it was.
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Starting with the iPod nano, the operating system was signed with a digital signature to block the Linux hackers (and others). The boot ROM checked the digital signature before loading the operating system; if it didn’t match, it wouldn’t boot.
Update (2020-08-19): See also: Hacker News.
From the article:
>I gave them a copy of the current source code on a
>DVD and explained it couldn’t leave the building.
But... you literally helped them build a tool that would allow them to secretly take data out of a building, a tool of which nobody else in your building knew!