sibrahim

6 ms·

1.
by sibrahim 8mo ago
That's what's covered by the "assuming you have formalized the statement correctly" parenthetical. Given a formal statement of what you want, Lean can validate that the steps in a (tedious) machine-readable purported pro
2.
by sibrahim 3y ago
It depends on whether you are doing something security critical with the result. Maybe you have a trusted table hash but only a user-supplied version of the table. Before you use that data for security sensitive queries, you should verify i
3.
by sibrahim 3y ago
XOR is not a great choice here. Consider that 2 copies of a row give the same result as 0 (or 4, 6, etc). And even without multiple copies of rows, you can force any hash you'd like by observing what happens when you insert more random
4.
by sibrahim 4y ago
Sometimes these are officially sanctioned and even required! Most notably, including logos/other embellishments are a form of "trap street" where the idea is to have something to point to that trivially proves someone is usin
5.
by sibrahim 4y ago
The usual next difficulty is that the maximum shebang length is fairly low (truncated at 128 chars, IIRC)
6.
by sibrahim 4y ago
Right. There's not a compelling reason to switch and there's more than a hint of CYA mixed in with Chesterton's Fence: https://www.bloomberg.com/news/articles/2016-06-09/how-intel... > For
7.
by sibrahim 4y ago
My understanding is that was the original purpose, but probably unnecessary given that all the relevant process steps are encased in tools that are not exposed to the general clean room environment in operation (they have to maintain a high
8.
by sibrahim 5y ago
If I wanted to keep the blur aesthetic, I'd probably do a full removal, run an inpainting algorithm to replace the removed region with something less jarring in context and then blur the result. The inpainting algorithm can be fairly
9.
by sibrahim 6y ago
As Izkata mentions, the superproject has _all_ the files for a given commit without any need for users to have access other repos, additional submodule init commands, etc. Basically, after a subrepo clone, you've copied the file tree f
10.
by sibrahim 6y ago
My preferred solution has been git-subrepo: https://github.com/ingydotnet/git-subrepo Basically is what (I think) submodules should have been. Creates a vendored copy with metadata about what commit it came from. Nor
11.
by sibrahim 6y ago
Note that the time taken is linear with respect to the original execution. A cycle of n instructions starting at instruction n0 will be detected in between n0 and n0+n iterations (i.e. <= 3*(n0+n) underlying instructions) since n0 iterat
12.
by sibrahim 6y ago
There's no need to store all previous states to detect a cycle: it can be done using just twice the original memory. You can model the state transitions as a linked list and use Floyd's classical tortoise and hare algorithm to (ev
13.
by sibrahim 10y ago
I've had success using \import{subdir/}{BasenameInSubdir} from the import package. The basic (and unfortunate in a xkcd/1479 way) issue appears to be that the arXiv compile server doesn't allow writing to subdirectories.
14.
by sibrahim 10y ago
That's certainly been my experience. I've had arXiv automatically block bare uploads of TeX-derived PDFs (presumably identified through PDF metadata). For these, it required that the source be uploaded and compiled on their serve
15.
by sibrahim 10y ago
Nothing, but no one will/should trust them without cryptographic expert consensus saying it's ready. Right now, the cryptographers most familiar with it are working on/with the official team and aren't clamoring to rele
16.
Fixing Vulnerabilities in the Zcash Protocol(z.cash)
63 points by sibrahim 10y ago|10 comments
17.
by sibrahim 10y ago
We did, in a way. One of the sources used was random.org (uses radio receivers tuned to static from atmospheric noise: hardware RNG as a service). I also had less than 3 weeks to take it from proposal to production. Combining two independe
18.
by sibrahim 10y ago
Anything that reseeds during operation can qualify. In fact, if the CSPRNG's internal state isn't large enough, you need to periodically reseed or face the same objection. But a CSPRNG which you need to explicitly seed with rando
19.
by sibrahim 10y ago
I had a rather specialized case where it was the pragmatic choice (note, not technically required): running a lottery with potentially litigious losers. If you used a CSPRNG with a seed space smaller than the set of possible lottery outcome
20.
by sibrahim 10y ago
For anyone else that's curious, the lottery problem is called the Transylvanian lottery: https://en.wikipedia.org/wiki/Transylvania_lottery The primary observation is if you want to match k numbers on tickets wher
21.
by sibrahim 10y ago
Lottery designer here. Some clarifications on the article: Re: getting a random number from 1 to 5 from a d6, my point got stripped out of the article and it's possible to come away with the wrong impression. Modular arithmetic is th
22.
by sibrahim 11y ago
This may be true for now, but if/when scalable quantum computing arrives, the recorded key exchange can be used to recover the session key (much easier than attacking AES itself). If you need confidentiality in the face of quantum adv