I think he wants to remove the downgrade protection and also allow machine code execution.

@bwang: Ndless2 sounds dismal... so I thought that I should try to crack it and develop an exploit.
A little bit of general discoveries for now though.

I still am confident that we will see Ndless 2.0 some day.  Last I heard, progress had stopped, but not ended, also, that was during the end of the school year, when progress on projects usually slows.

EDIT:100 Posts!!!! 

Just wondering... does the TNS format need cracking?

From what I've read, the calc does get a little upset if you send it a ZIP file instead of it's special compression format.
I don't know about software side though. (I played around with a friend's Nspire and unlocked its true potential with Ndless. He loved it. )

Quite frankly, I would need a TI Nspire to really do some hacking, but I don't have one, and I don't think I'm going to beg for one here...

It's possible that a hacked TNS could open exploits for the calc.
The TNS contains XML files. The XML files are parsed by expat. (Version 1.95.8 for reference)

However.... expat doesn't really (at least not mentioned on their page) have any security issues.
A recent one is something to make it go loopity loop (infinite loop, aka DoS attack), which doesn't really seem helpful.
(Maybe hilarious to watch the Nspire freeze?)

@graphmastur: The only way around it is releasing a new line of calculators. You can't just change the keys overnight and expect them to work on all the Nspire calcs.

I'm just suggesting ideas. I'm not the person who does this kind of stuff. I've started some preliminary prime number analysis, but otherwise, nothing much at all. Monsieur Debroux might be able to do it, but he, like you, is unwilling to. Just another random idea: rent Amazon/Sun Microsystems servers, and use that. (Of course, it has to be donation funded. Sun Microsystems does give free usage for some projects, but I doubt cracking RSA keys is one of them...)

(Sigh....)
It's actually quite interesting really. RSA cracking is basically finding 2 prime numbers that multiply each other to get a final number (which I think is the public key).

It's basically finding 2 numbers that multiply each other to give the final key.
It's kinda sad really that mathematics is the thing that's preventing all of this...

To anyone out there:
1) Does the TNS format still need cracking?
2) Which key on the Hackspire wiki do we need?

@Lionel Debroux: Ahh, I see. Looks like you are part of the few who can't do much this summer!
Are you a math teacher by any chance? (I've heard that some people here are math teachers... which could explain why they are busy)

The CLI program might be OK to implement, but I'm not really familiar with the code. I'll see if I can write something.

Anyway, back on topic...

Is there any Nspire emulator that works on Linux and is compatible with the latest OS?
I've tried numerous times to get the emulator (windows, latest) to work, but it's pretty buggy.

Oh, I missed the post of alberthrocks you're quoting.

The difficulty of factoring integers is not intuitive: for the task of factoring a 1024-bit number, we're too low on resources by orders of magnitude

1) the naive trial factoring (TF) algorithm would require ~1e155 trial divisions, i.e. even more electrons. The trouble is, the estimated number of atoms in the universe is ~1e100, and the number of electrons is less than ten times that amount. That TF yields a factor in 1e13-1e20 steps is sooo extremely unlikely. My computers have performed ~3.1e12 trial divisions on the OS signing key, and I'm planning to let them perform up to ~1e13 trial divisions on the boot2 key - but going beyond that would be unreasonable.

2) we can't use the only not-completely-impractical algorithm, GNFS, because it requires a terrifying amount of computing power and storage space, and because we don't have the appropriate implementations. Let's just use the figures in the research paper detailing the factorization of RSA-768, made by the top researchers of the field:
* RSA-512 requires several gigabytes of storage space, it can nowadays be done in a home computer in a couple months (we confirm the numbers for the TI-Z80 and TI-68k keys);
* RSA-768 was, as written in the paper, a task several thousands times harder than RSA-512, and it required ~10 TB;
* RSA-1024 is said by the top researchers of the field to be a thousand times harder... see where that leads ?
And that's before I even mention that the factorization of RSA-768 was obtained through highly special algorithms and implementations (not made public), which are likely to require further improvements to scale up three orders of magnitude...

If you want more information, and a program that you can make your processors work on (it might, even if extremely unlikely, yield a miracle), read the entire http://www.omnimaga.org/index.php?action=printpage;topic=3639.0 topic. Use my version, and switch to the 0xc3b3... key.


And nope, I'm not a math teacher. I'd have more free time during the summer if I were.

But then again... wouldn't the likeliness that we would have to hit all the combinations be low?

Unfortunately, no.

Could you possibly code it so that if I hit CTRL-C (or hit a key to quit the program), it saves the key?

It's possible, but harder (portability problems). I'm myself using CTRL + C and redirecting the output to a file, which enables me to resume using `cspire -r 0x...` the next time.

I think critor was the guy I was thinking about that is a math professor...?

Yes, critor is a math teacher indeed.