knweiss | 2 years ago | on: Ask HN: I’m an FCC Commissioner proposing regulation of IoT security updates
knweiss's comments
knweiss | 3 years ago | on: Apple's feedback mechanism is broken
Also, take a look at their user forums: They are full of bug reports with hundreds of users having the same problems - and nothing happens. I really wish they would react much better with official acknowledgments, references to open bugs, workarounds, etc. It is depressing how much collective time is wasted.
knweiss | 3 years ago | on: 100 People with rare cancers who attended same NJ high school demand answers
knweiss | 6 years ago | on: AMD is dominating Intel in Amazon's best-selling CPUs list
The source code is available on GitHub.
knweiss | 8 years ago | on: Spectre Mitigations in Microsoft's C/C++ Compiler
I'm mentioning this because (at least to my understanding) in Spectre variant 2 the entire address space of the victim process can be used to find the "gadget" i.e. an usable target for the indirect branch. This means that making only your input validation code "spectre-free" is not good enough for variant 2. (This is why e.g. OpenSSH recently started using the (Spectre variant 2!) retpoline compiler flags of GCC/LLVM if available. See this thread for details: https://lists.mindrot.org/pipermail/openssh-unix-dev/2018-Fe...)
knweiss | 9 years ago | on: Linus on Git and SHA-1
knweiss | 9 years ago | on: How is NSA breaking so much crypto? (2015)
"When performing Diffie-Hellman Group Exchange, sshd(8)
first estimates the size of the modulus required to
produce enough Diffie-Hellman output to sufficiently
key the selected symmetric cipher. sshd(8) then randomly
selects a modulus from /etc/ssh/moduli that best meets
the size requirement."
The problem isa) OS distributions ship pre-computed moduli in the /etc/ssh/moduli file. I.e. most users don't change these moduli. This facilitates pre-computation attacks.
b) These moduli are often too short (<2048 bit).
You can create your own moduli with ssh-keygen (see the "MODULI GENERATION" section in the ssh-keygen manpage).
FWIW: Here's my open bug for RHEL7 where I try to convince Red Hat to improve the situation (including more details and references):
knweiss | 9 years ago | on: Ask HN: Is there a “ground-up” explanation of PGP/GnuPG?
https://begriffs.com/posts/2016-11-05-advanced-intro-gnupg.h...
knweiss | 9 years ago | on: Dropbox employee’s password reuse led to theft of 60M+ user credentials
knweiss | 9 years ago | on: How climate change is rapidly taking the planet apart
knweiss | 9 years ago | on: Apple File System
knweiss | 10 years ago | on: Google XRay: A Function Call Tracing System [pdf]
"Sampling profilers, the most common performance debugging tool, are notoriously bad at debugging problems caused by tail latency because they aggregate events into averages. But tail latency is, by definition, not average."
knweiss | 10 years ago | on: It takes two to ChaCha (Poly)
Quote:
On Haswell, one AVX instruction on one core forced all cores on the same socket to slow down their clockspeed by around 2 to 4 speed bins (-200,-400 MHz) for at least 1 ms, as AVX has a higher power requirement that reduces how much a CPU can turbo. On Broadwell, only the cores that run AVX code will be reducing their clockspeed, allowing the other cores to run at higher speeds.
knweiss | 10 years ago | on: Distribution packages considered insecure
The latter should be a signal for the distribution to upgrade to a newer and supported upstream version instead of (halfheartedly) trying to support the software themselves.
knweiss | 10 years ago | on: Making a 4K Fractal Movie with Fractal EXtreme
knweiss | 10 years ago | on: Intel's 72-Core “Knight's Landing” Xeon Phi Chip Cleared for Takeoff
[0] - http://www.anandtech.com/show/9794/a-few-notes-on-intels-kni...
knweiss | 10 years ago | on: Subresource Integrity
IPFS comes to mind.
knweiss | 10 years ago | on: Ask HN: Where can I learn more about programming video and audio codecs?
knweiss | 11 years ago | on: AEADs: getting better at symmetric cryptography
knweiss | 11 years ago | on: Last Week Tonight with John Oliver: Government Surveillance [ft. Edward Snowden]