Author Topic: Virus to crack RSA for nspire? :P (Read 69591 times)

fb39ca4 · « **Reply #90 on:** July 10, 2010, 06:06:10 pm »

That's interesting. Maybe we could emulate a power fluctuation in Goplat's emulator.

calcdude84se · « **Reply #91 on:** July 11, 2010, 04:43:47 pm »

We wouldn't need to. Since it's an emulator, we have full control over what's happening inside.
The problem, however, is that the private key is used for signing, but the Nspire only contains the public key. (The private key is held by TI.)

willrandship · « **Reply #92 on:** July 11, 2010, 11:36:34 pm »

Hence why I said it doesn't apply to the nspire. Too bad though. That emulator idea sounded cool!

I still like the idea of replacing the public key, by using an arm asm program. It might be possible, I'm not sure. Plus, you invalidate the Standard OS in the process. Who cares about that one, anyways, as long as we get a z80 emu?

It's only good for math anyways. I'd love to see an 89-style GUI on it, personally.

DJ Omnimaga · « **Reply #93 on:** July 11, 2010, 11:55:49 pm »

I wonder if Ndless 2.0 ever never comes out if it will eventually be possible to just make a third-party OS and add TI-Nspire linking support for every possible OSes and be able to send it to the Nspire?

bwang · « **Reply #94 on:** July 12, 2010, 12:14:44 am »

We should just port Linux.

DJ Omnimaga · « **Reply #95 on:** July 12, 2010, 12:21:02 am »

True!

If people do so, they should try to port an user-friendly version, though, for people who hate having to use command console to do every single thing

Lionel Debroux · « **Reply #96 on:** July 12, 2010, 12:34:39 am »

Hackspire says that the files containing the public keys are themselves signed with a 1024-bit RSA key. TI is not _that_ stupid

Builderboy · « **Reply #97 on:** July 12, 2010, 01:41:00 am »

Lol, encrypting encryptions? I guess TI really didn't want these keys factored

So do we even have the *public* keys?

Tribal · « **Reply #98 on:** July 12, 2010, 01:49:07 am »

Yeah, we have the public keys, otherwise we wouldn't have a reference point for the factoring programs. IIRC they were acquired due to some error on TI's part, but I may be wrong.

Lionel Debroux · « **Reply #99 on:** July 12, 2010, 05:04:14 am »

The public keys are simply embedded in OS upgrades files, either in clear binary (TI-Nspire.cer), in compressed form (boot2.img) or in encrypted form (TI-Nspire.img)

See http://hackspire.unsads.com/wiki/index.php/OS_upgrade_files , linked multiple times in this topic.

In TI-68k calculators, the keys are in clear binary. They probably are on TI-Z80 calculators, too.

DJ Omnimaga · « **Reply #100 on:** July 12, 2010, 12:09:26 pm »

Did you just need to rename the .tno/.tnc file to .zip and grab the stuff inside?

Lionel Debroux · « **Reply #101 on:** July 12, 2010, 12:46:23 pm »

Yes and no, it depends on your ZIP reader program

Mine (ark on Linux) handled the .tno/.tnc as a ZIP file properly, but it printed a note that there was some leading garbage.

DJ Omnimaga · « **Reply #102 on:** July 12, 2010, 01:06:13 pm »

Aaah ok. I remember WinRAR opened my .tno files fine, same for .exe.

willrandship · « **Reply #103 on:** July 15, 2010, 08:15:43 pm »

I had an idea for simplifying the key decryption that doesn't involve algorithms.

Right now, it decrements by 2 every time. That makes the ending numbers look like this
9
7
5
3
1
9
7

5 will never be the last number in a factor. what if, instead of subtracting by 2, we had 4 computers (or more, obviously) subtracting by 10? The program is no more complicated than before, it should run just as fast. Therefore, we should get a 1/5 decrease in time.

Yeah, it's farfetched, but it's worth it if it works, right?

I'll check out tribal's C program. It should be a bit more readable than the perl script for me, and it works faster anyways.

Edit: Tribals already only checks primes. Never mind....my optimization only works for the perl script

jnesselr · « **Reply #104 on:** July 15, 2010, 08:27:42 pm »

Also, if you are looking for only p, where p is the lower prime, and q is the higher, you could try 0 through 9 for p, and see which ending digits are the same. Take 221 for example. It's prime factor is 13 and 17. There are only three possible ending numbers, 3x7 and 9x9 and 1x1.

This is a list of the ending number, and the numbers that the primes would have to end with:
1: 1x1, 3x7, 9x9
3: 1x3
7: 1x7, 3x9
9: 1x9, 3x3, 7x7

So if my theory and math is correct, which I'm pretty sure it is, then the number ending with 3 is your best case, and 1 and 9 are your worst case. (Using your theory of adding 10)

Author Topic: Virus to crack RSA for nspire? :P (Read 69591 times)

fb39ca4

Re: Virus to crack RSA for nspire? :P

calcdude84se

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willrandship

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DJ Omnimaga

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bwang

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DJ Omnimaga

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Lionel Debroux

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Builderboy

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Tribal

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Lionel Debroux

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DJ Omnimaga

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Lionel Debroux

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DJ Omnimaga

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willrandship

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jnesselr

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