For Texas Instruments, Calculator Hackers Don't Add Up

Re:For Texas Instruments, Calculator Hackers Don't Add Up by unwind on Thursday October 29, 2009 @10:32AM (#910049)

I'm not sure about the details, but perhaps they're afraid that if the ROM key is broken, people can more easily read out the ROM code, and use it in a cheap clone of the hardware?

There might be a larger monetary value associated with the actual OS code, than with the hardware design itself.

As I said though, I'm not sure about the details here; you'd of course expect the CPU on the calculator to be able to access the ROM code in order to run it, but perhaps it's somehow obfuscated when that happens.

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Re:For Texas Instruments, Calculator Hackers Don't Add Up by daeken on Thursday October 29, 2009 @10:38AM (#910066)

This is purely a signing key. It's not used for any sort of copy protection but solely to prevent unauthorized code from running.

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Re:For Texas Instruments, Calculator Hackers Don't Add Up by kwantam on Thursday October 29, 2009 @10:37AM (#910061)

My understanding (which is incomplete) is that this is only a signing key.

Even if they are somehow relying on this key to prevent cloning, are they seriously under the impression that a 512-bit key is sufficient to keep a bunch of guys in Shenzhen from making a firmware-compatible device? Any effort to clone has long since come to fruition, and it's extremely likely they know this.

My guess: lawyers justifying their existence by picking fights with people they expect can't fight back. I'm glad the EFF has stepped in.

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Re:For Texas Instruments, Calculator Hackers Don't Add Up by duskwuff on Thursday October 29, 2009 @10:54AM (#910104)

It's not even keeping anyone from cloning, because a Chinese manufacturer could just copy the ROM wholesale, signing key and all. Or patch out the signing key checks, or replace the key with one of their own... quite literally, the only thing this key is doing is keeping device owners from installing unauthorized applications and replacement OSes.

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Re:For Texas Instruments, Calculator Hackers Don't Add Up by reedlaw on Thursday October 29, 2009 @10:49AM (#910089)

Didn't this hacker make a replacement OS better than TI's? I don't think TI will face serious competition from clones, except possibly in Asia and third-world countries. This hack doesn't even help in making clones, except maybe by giving engineers a chance to practice programming calculator OS's.

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