For Texas Instruments, Calculator Hackers Don't Add Up

http://spectrum.ieee.org/consumer-electronics/gadgets/for-texas-instruments-calculator-hackers-dont-add-up/0

by naish • 17 years ago

81 90 17 years ago

spectrum.ieee.org

jgrahamc3• 17 years ago

If you use a 512-bit RSA modulus then you are asking for it to be factored. I am in the process of factorizing the 512-bit RSA modulus of a very famous company and will disclose it (responsibly) once it is done. Factorizing keys of that size is doable on high-end consumer hardware with a little patience.

Shamiq• 17 years ago

How much patience?

jgrahamc3• 17 years ago

A couple of months.

brown9-2• 17 years ago

Doable with how much patience exactly?

wallflower2• 17 years ago

The original forum thread was entertaining to read after the fact (parts have since been redacted).

"Oh my good lord...

You need to explain how you did this. Now. To somebody.

EDIT: I just confirmed this is what I think it is. This needs to go to ticalc.org. Are you being intentionally cryptic about this and want to stay unknown?"

http://www.unitedti.org/index.php?showtopic=8888

(via http://news.ycombinator.com/item?id=771736)

daeken2• 17 years ago

Repost of the original message that started it all -- spread it far and wide:

    Gentlemen,
    A mathematical morsel for your entertainment and edification.
    
    The number
    6,857,599,914,349,403,977,654,744,967,
    172,758,179,904,114,264,612,947,326,
    127,169,976,133,296,980,951,450,542,
    789,808,884,504,301,075,550,786,464,
    802,304,019,795,402,754,670,660,318,
    614,966,266,413,770,127
    
    is the product of
    5,174,413,344,875,007,990,519,123,187,
    618,500,139,954,995,264,909,695,897,
    020,209,972,309,881,454,541
    
    and
    1,325,290,319,363,741,258,636,842,042,
    448,323,483,211,759,628,292,406,959,
    481,461,131,759,210,884,908,747.

csbrooks• 17 years ago

It highlights the absurdity of the whole thing, really. It seems hard for TI to argue that it's illegal to post a mathematical fact, doesn't it? Especially one that's so concise and straightforward.

zackattack3• 17 years ago

You're neglecting the importance of context.

hy3lxs• 17 years ago

I'd have to say the absurdity of the whole thing is that calculators are allowed on math tests at all, thus fueling an entire market of crippleware calculators.

(1) If you're trying to teach mathematical _concepts_ then make your problems come out to whole numbers that are easily done with pencil and paper.

(2) If (1) was true then maybe we'd see some real innovation in the calculator space, especially if the single-purpose electronic device costing $100 from TI had to compete with iphone apps costing $1. Or Google Calculator. Or Wolfram Alpha.

(3) I've anecdotally heard from my math-tutoring friends that there is a growing pandemic of high school kids in America that can't multiply single-digit numbers anymore. O_o

alain940402• 17 years ago

This is where common sense comes into play. If you were in front of a judge, your argument that you are just posting a mathematical fact wouldn't stand for more than 10 seconds.

Tell the truth: why did you choose those two numbers, specifically? Oh, because they allow you to unlock a TI calculator. So (the judge would say), you are publishing a secret key. You are not publishing random number products for the fun of seeing how many digits your calculator can handle.

Taken to the extreme, this is the same argument as a hacker saying: I didn't break into the bank's computers, I just wrote a program, and the program is the one that broke into the bank. I was just typing on a keyboard, that's all I did.

Intent.

kd5bjo• 17 years ago

I imagine they might have some sort of trade secret claim, but I don't think that provides any protection from independent discovery. (IANAL)

lucifer• 17 years ago

" It seems hard for TI to argue that it's illegal to post a mathematical fact".

Yes, absurd, but if you can patent genes (!) is it that much of a stretch to assert copyright on specific numbers?

http://www.ornl.gov/sci/techresources/Human_Genome/elsi/pate...

niyazpk• 17 years ago

I don't think it is so simple as that. In this thread many people are arguing something to the effect of "factoring numbers and posting it online is not illegal".

I tend to disagree. Not with the argument itself, but with the deception in covering the original issue with a much toned down one. The hacker who did this was not trying to innocently post the results of some factoring problem. He posted the results to a specific factoring problem. Then he posted an article titled "83+ OS signing key cracked!". Clearly he was not trying to just factor those numbers.

How Texas Instruments should have ideally reacted to these results is debatable, the fact remains that what the hacker did was not pure white.

How would you feel if somebody figures out your SSN and post it online? Is it just another mathematical truth that is allowed to flow freely through the universe?

Dear HN, everything cannot be explained by math.

reedlaw2• 17 years ago

What could TI's motivation possibly be? How could they lose any business by hackers modifying firmware? Instead, it seems it would be more likely to increase hardware sales.

unwind• 17 years ago

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.

kwantam2• 17 years ago

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.

daeken2• 17 years ago

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

reedlaw2• 17 years ago

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.

JulianMorrison• 17 years ago

Are they trying to get away with selling cheap low-features versions that aren't different except in software?

spicyj2• 17 years ago

This would be plausible except AFAIK all of their models have different hardware capabilities. The 83 and 84 even un the same exact software; they just have different specs.

ralphc• 17 years ago

I'm thinking it goes something like this. The TI calculators have something called "press-to-test", where a teacher can hit a combination of keys to disable functionality on the calculator. When in this mode, a LED flashes on the calculator so a teacher can tell at a glance that the student isn't "cheating".

Now imagine a homebrew OS where you hit the "press-to-test" keys, and the light blinks, but all the calculator's functionality is still there. If this became prevalent, then schools could outright ban the calculators on tests, so students would be less likely to buy them. Lost sales from this would dwarf any pickup from home hobbyists.

warfangle• 17 years ago

Bah; they should all just use slide rules anyways. /sarcasm

yrb• 17 years ago

That doesn't sound like something that couldn't be bypassed already with just a tiny bit of hardware hacking.

Nekojoe2• 17 years ago

I think this is down to the educational market. For many exams you can only used an approved make/model calculator.

If you can hack the OS you can use it to store answers, notes or similar aids in cheating for an exam. If the platform isn't locked down they'll lose their exam board approval which would have a big impact on that models sales.

spicyj2• 17 years ago

I don't think TI is still selling the 83; they've moved on to promoting the supposedly new and improved N-Spire.

gcv• 17 years ago

Tom Cross, a security technology researcher in Atlanta, received a cease-and-desist letter from TI after merely posting about the hackers on his blog, ... [and] took down his link.

Excuse me, taking down a link to a discussion of the key? Does the DMCA really extend that far? If it does, it really sounds like it could be challenged on First Amendment grounds. Otherwise, either this guy has no backbone, or there is more to the story.

scott_s• 17 years ago

It's easy to posture how you'd fight The Man when it's not you who's threatened with financial ruin and the time equivalent to a second job.

pasbesoin• 17 years ago

My comment is largely reiterative, but important enough to emphasize.

It's not the law as written, but as it plays out in the larger socio-economic sphere, that is often determinant. It doesn't matter what your rights are, if the other guy can spend you into the ground with impunity.

Taken to extreme, it's one reason we regulate monopolies (in the U.S.). You may come up with a better product, but if the other guy has a lock on the market...

If you don't have the resources, the wherewithal yourself to execute the fight, how do you make it? On your own, your one option is the shop for a lawyer who believe you have enough of a chance that their willing to invest in the effort (in return for a hefty share of any judgment in your favor). If you are fortunate, the EFF or another organization may take up your case and use the pooled contributions of its members to fund the fight.

Even then, what will the publicity do to your career and other aspects of your life, depending on who you work for, etc. Fighting such things, one way or another, is important, but it is not easy and not everyone has the means, financial or otherwise. The means to fight, and/or the means to survive if the judgment (and penalties) goes against them.

kwantam2• 17 years ago

The more fundamental question here: can the DMCA really be used to prevent a person from factoring a number and disclosing the results? This is insanity.

jcl2• 17 years ago

I'd guess that it can, if that number is being used to protect a copyrighted work. That sounds like exactly a situation that the DMCA was designed to make illegal.

ars2• 17 years ago

It's not though. It's protecting hardware, not software.

It's not stopping copyright violation at all. It's preventing "unauthorized" software from running on the hardware.

I simply don't see how the DMCA applies here. In fact I can't see how any copyright law at all applies here.

No one is copying any code, they are running their own code. The key they found convinces the device to use their code.

rbanffy2• 17 years ago

No, but yes.

It's not that the number is being used to protect copyright - it's a signing key that prevents you from installing different software on your calculator.

But yes. The DMCA has the provision about publishing DRM circumvention techniques and tools. This seems to be one.

Stupid and unfair, BTW. TI is hurting itself more than its user base.

monocasa2• 17 years ago

Actually the DMCA has an exemption for allowing software interoperability. This sounds like exactly the situation that it was designed not to protect against.

forinti• 17 years ago

Even if they used something simple, such as rot13? That would be funny...

mustpax• 17 years ago

Well, people have been sued for breaking ROT13, no joke:

http://news.zdnet.com/2100-9595_22-116424.html?legacy=zdnn

zackattack3• 17 years ago

Anyone else think that picture resembles a headline from The Onion?

billybob• 17 years ago

In the last 10 years, computers have advanced tremendously. Why do I still see the same TI-whatever calculators in on the store shelves? They don't need to play video or browse the web, but you'd think they'd at least be thinner.

Does TI have any competitors? Do they have an exclusive agreement to supply calculators that can be used on standardized tests?

CamperBob• 17 years ago

Do they have an exclusive agreement to supply calculators that can be used on standardized tests?

In a great many cases, yes. That's why they never seen to change or innovate, and also why they're coming down like a load of bricks on anyone who hacks their firmware.

genieyclo2• 17 years ago

Link to Brandon Wilson's site with the key back up: http://www.brandonw.net/

Link to a letter from TI: http://www.brandonw.net/calcstuff/DMCA_notice.txt

jrockway9• 17 years ago

Good to see that he decided not to cave and is retaining legal counsel.

rick_20474• 17 years ago

umm...amidst of all these no-doubt informative discussion, I found no one here appreciated how cool Hardware Hacking can be. And when it is done with something as minimalist as a Calculator(while these have more power than the first PDPs at MIT labs),there is just one word for it MIND BLOWING. I mean...look at them, they are making fcking GAMES for these. DUDE even FPS?A FPS on a calculator,in your face X-Box.

pwmanagerdied• 17 years ago

Get the fuck off this site.

rick_20474• 17 years ago

Ok the mentioning that they are cool can be a bad post but not that bad dude.Cool your heels

rick_20474• 17 years ago

Okeyyy...If I getting down voted these many times,hardware hacking may not be cool.Or did something else ticked someone off?Please any comment might help me understand what is so offensive about this post.

pmjordan• 17 years ago

I'd guess that your tone, combined with the borderline off-topic-ness and the fact that you haven't really added anything to the conversation ticked people off. I wouldn't and didn't downvote you based on that comment, but certainly wouldn't upvote. I suspect if you'd phrased it differently and maybe made it a little more useful, people would have responded differently, e.g. "I really admire these calculator hackers, it's amazing what can be done on these simple machines, e.g. these cool games: [link], [link] and [link]."

The HN userbase appreciates a high signal/noise ratio. Merely calling something "cool" is considered noise.

Hope that helps.

rick_20474• 17 years ago

Does anyone know if such mods can be done on calculators with no programming power?Like casio Fx- series. I have a fx-911MS so was just curious.

For Texas Instruments, Calculator Hackers Don't Add Up

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