yifanlu

13 ms·

61.
by yifanlu 10y ago
> The number of people who gave an opinion on quantum computing is 16. > 1 said quantum computing is a hoax. Wow.
62.
by yifanlu 10y ago
So, your concern with password managers right now is that losing your master password means you lose everything? You wish to design a new system where the threat model includes losing the master password? I think your implementation only ad
63.
by yifanlu 10y ago
In terms of security, this doesn't improve anything (all security hinges on the master password). In terms of flexibility, this is a lot worse than a secure password manager.
64.
by yifanlu 10y ago
No. Let's see what happens if this same story is told without the racism. Bob is on the phone with his mother and said he will have a "salad" tonight. Sally across the aisle heard it as "suicide" and reports him. Th
65.
by yifanlu 11y ago
> i wonder why anyone thinks open problems in number theory are a sound means of crypto The short answer is that the numbers are so large that with current state of the art means (which I'm sure you know a lot about), factoring a 20
66.
by yifanlu 11y ago
Of course, in a perfect world we would all be doing that. However, there is a tradeoff of boot-time/power consumption/hardware complexity (the hw AES engine only does CCM/CTR/CBC). Given their track record though, I woul
67.
by yifanlu 11y ago
You may not mean it this way, but for any reader who might be mistaken: P == NP => integer factorization can be done in polynomial time with a classic computer but not vice versa. In fact, many people believe P != NP && integer f
68.
by yifanlu 11y ago
So we have FIRM, the main firmware image. It has three segments: 1) main ARM11 kernel modules, 2) ARM11 kernel, 3) ARM9 kernel/ARM9 process. The FIRM header has a SHA256 hash over all the segments and the size of all segments. The FIRM
69.
by yifanlu 11y ago
First, the 3DS mostly uses RSA for code signing, something I didn't really touch on since there's no serious mistakes there. Second, while RSA does not fair well against quantum attacks, as of today, there is still no way of facto
70.
by yifanlu 11y ago
As a simplification, I did not draw any of the blocks contributing to code signing. RSA is used everywhere to ensure that the code is signed. If you consider the signature as the MAC, it does "Authenticate Then Encrypt" (the signa
71.
by yifanlu 11y ago
Well the first break that brought piracy happened about two years after launch. Also, the Vita, which launched around the same time is sill unhacked pretty much. It's a shame that there's not as much good games on there for it to
72.
The 3DS Cryptosystem(yifan.lu)
120 points by yifanlu 11y ago|49 comments
73.
by yifanlu 11y ago
How well does it defend against this deobfuscation approach? https://www.cs.arizona.edu/people/debray/Publications/generi...
74.
by yifanlu 11y ago
I don't get that point. "Normal" users won't (and shouldn't) disable SIP. Those who do need to for security research won't really care that Apple knows they're poking into the system (when you disclose a v
75.
by yifanlu 11y ago
Okay, there's many problems with this post. First, most people do not need to use dtrace. Especially on system processes. They claim that this is bad for security researchers because they can't monitor the system anymore and they
76.
by yifanlu 11y ago
The outrage isn't that your luggage can be stolen now. The outrage is that a) the government felt that it needed to invade the privacy of our luggage for security; so they made these master keys (yes, you can pull them apart with your
77.
by yifanlu 11y ago
First, there is no "kernel exploits from vulnerable games" as games are applications that run in the OS (FreeBSD based). What happened with the PSP is that game exploits can be used to run code that trigger kernel exploits (which
78.
by yifanlu 11y ago
It is possible to create save files. However they will be tied to a specific console/account. And creating them requires a kernel exploit while a vulnerable game only gives you a userland exploit. It won't be the most practical ev
79.
by yifanlu 11y ago
No, because that breaks the signature.
80.
by yifanlu 11y ago
Yeah, it's unauthenticated encryption, but think about their threat model. It's not about protecting integrity (the code signing takes care of that), it's about protecting the code from prying eyes (aka DRM). And the tradeoff
81.
by yifanlu 11y ago
He is misquoting myself and/or other people who've talked about the encryption before. Sony has their own format they call SELF (secure ELF?) which works as follows: each ELF segment (not section) has a key/iv generated for i
82.
by yifanlu 11y ago
This uses an known (and patched) FreeBSD vulnerability (BadIRet). It only works on PS4 <= 1.76 (pretty old now) and is not publicly available (CTurt does not have permission to release it). I think this whole article is just an advertise
83.
by yifanlu 11y ago
I'm not making a judgment either way but you understand that Apple and Google chooses to only sell their things and Amazon choses to sell everything excluding these devices?
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by yifanlu 11y ago
https://research.cs.wisc.edu/vertical/papers/2013/isa-power-... Generally, the thought is that ISA doesn't really affect performance.
85.
by yifanlu 11y ago
And why should they last for more than a week if they break rules? Sure, you can argue that the rules are pointless but it would be arrogant for you and I to decide which rules we want to follow and which ones we can ignore. Maybe treating
86.
by yifanlu 11y ago
While a nice novelty, simulating TM on your computer is not that interesting. I mean you can do it with a single instruction: https://en.wikipedia.org/wiki/One_instruction_set_computer (or even zero instructions on x86
87.
by yifanlu 11y ago
Even if you had a devkit, you still won't know. The devkit is just as sandboxed and there's an additional processor whose sole job is to enforce security on the debugger and PC communications.
88.
by yifanlu 11y ago
Well if I can be pedantic for a second, "valid signing certificate" is much harder to find than any software exploit. In fact if you can find it without physically stealing the certificate, you just broke modern cryptography. And
89.
by yifanlu 11y ago
Well I don't consider them embedded, but I would say yes for the PS4. I haven't looked at the xbone yet so I can't say anything for that. PS4 uses FreeBSD9 as its kernel. Plus there is no KASLR. In theory, if you find an expl
90.
by yifanlu 11y ago
How detailed do you want me to get? I've hacked both of them so I can give you as much info as you want. From a broad perspective, Vita has KASLR/ASLR, stack canaries, trustzone, just to name a few standard things that 3ds doesn&#

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