
For Texas Instruments, Calculator Hackers Don't Add Up - naish
http://spectrum.ieee.org/consumer-electronics/gadgets/for-texas-instruments-calculator-hackers-dont-add-up/0
======
daeken
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
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.

~~~
hy3lxs
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

~~~
yequalsx
I teach mathematics at a college. Doing (1) for every type of problem is not
feasible. In college algebra courses we now give problems that involve using
the best linear, quadratic, or exponential fit. We definitely do not do these
problems by hand. The calculator is a black box that spits out the correct
approximation and the student is asked to answer questions based on what the
calculator spits out for the correct fit.

Part of our jobs is to prepare students to use mathematics in engineering,
physics, chemistry, etc. We don't want to always give problems where the
numbers are nice.

Is (3) a problem? How many people can find interpolating polynomials? Very
few. Interpolating polynomials are no longer needed by most students of
mathematics because computing power is cheap and ubiquitous. The skill set for
mastering mathematics has changed given this reality.

Think of it this way. Very few people can start fire without matches or flint.
This used to be common knowledge years ago but is no longer needed. Fire
making devices are cheap and plentiful.

~~~
RiderOfGiraffes
Do you want your doctor to look at your symptoms and start leafing through
reference books, or looking on Google to decide what you have? It doesn't
matter how clever you are, or how good at reasoning, you have to have basic
knowledge to use as the base.

AI researchers came to this conclusion a long time ago. Reasoning or
experience is not enough - you must have codified, accessable knowledge on
which to work.

Not knowing basic arithmetic cripples you when you need to work on the next
stage. Not knowing that 7*8 is 56 means you can't work out the expansion of
(x+1)^8. Working simple cases like that makes it clear what's happening when
you differentiate, and gives insight that you can't obtain without doing the
work.

The maxim from medicine is "See one, do one, teach one." The middle step is
crucial. If you get the computer to do everything, you never gain the
experience, and rarely have the insights.

And, personally, I can interpolate polynomials. It's an interesting example,
because recently it allowed us to implement a new feature in our system. No
one else to work out how to do it, and were amazed when I did.

In your terms, I can make fire in a world where most people can't. It just
earned us real money.

~~~
yequalsx
Interpolating polynomials used to be taught in high schools. I learned it in
high school and today almost no high school graduate knows how to do this. Is
this a bad thing? I don't think so. With new technology and the advancement of
ideas and knowledge the basic skill set that is necessary changes.

The division of labor has rendered many once necessary skills the province of
specialists. This is a good thing. Is arithmetic one of those things? I begin
to believe so. The expansion of (x+1)^8 does not require the ability to do
7*8. One can do the expansion using Pascal's Triangle.

Besides, the real question is ought one do the expansion of (x+1)^8 by hand?
The answer is no. The expansion is a purely mechanical process. A computer
does it faster and more accurately. In such a long problem I am likely to make
a mistake and this mistake does not mean that I don't know what I am doing.

I do want my doctor to thumb through reference books particularly if my
condition is rare. In such a case it is unlikely that the doctor will have
encountered my condition and I want her to gain from the shared experience and
collective wisdom of experts. That's what a reference book is for and it's a
good thing. I want my doctor to be able to read and understand the book. That
is what her training is for.

One can get insights into algebra using a computer. It's just that the
insights are different than what one could get without a computer. Instead of
teaching interpolating polynomials in high schools they are teaching basic
statistics and in this present age the latter is much more beneficial than the
former.

~~~
RiderOfGiraffes
I'm sorry I can't convince you, but I've done both, and I know that insights
are given in both realms, doing things by hand, and using the computer. To
throw away one is to lose an advantage.

The point of doing the expansion of (x+1)^8 (to continue the example) is not
to get the answer, but to see the patterns building. You say you can do it
easily enough by using Pascal's triangle, but finding that insight alone is
worth the time.

Just last week I saw someone differentiate x^(1/2) by using a calculator to
convert 1/2 to a decimal, putting it at the front, then carefulyl subtracting
1 from it, and getting 0.5 x^(-0.5). Right answer. Then they did the same for
x^(1/3) and got 0.334 x^(-0.667) and got full marks. Follow the process by
rote, and don't think.

I know I'm fighting a losing battle, because "Get the computer to do it" is
too easy. What is lost is hard to see, and once it's gone it's impossible to
regain. I wish I'd learned a langauge when I was 15 or younger, instead of now
when I'm nearly 50. I'm constantly surprised that I can get answers to
questions far, far faster than my colleagues and employees using techniques I
learned when I was 12. I'm not using experience or any great gift, I'm using
what everyone was taught in school at that time.

It's still useful. Perhaps I should be grateful that these skills are
disappearing because I'm certainly never out of work.

------
jgrahamc
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
How much patience?

~~~
jgrahamc
A couple of months.

~~~
paulgb
Out of curiosity, what sort of hardware is typically used for this?

~~~
ars
CUDA, with high end NVidia video cards.

~~~
monocasa
Actually, I think he did it on a significantly less powerful system. Just an
Athlon64x2 or similar. CUDA could speed it up considerably.

------
kwantam
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.

~~~
jcl
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.

~~~
ars
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.

~~~
jcl
My impression was that he was asking about factoring in general, not
specifically in relation to the TI.

------
gcv
_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
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
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.

------
wallflower
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>)

------
reedlaw
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
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.

~~~
kwantam
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.

~~~
duskwuff
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.

------
genieyclo
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>

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

------
billybob
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
_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.

------
rick_2047
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.

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

------
rick_2047
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.

~~~
rick_2047
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
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.

