kmowery

5 ms·

1.
by kmowery 8y ago
One of my favorite vim plugins is https://github.com/sjl/gundo.vim , which can open a pane showing the actual tree of versions, including at what time the version changed. j and k can move around in the tree, and the p
2.
by kmowery 12y ago
The starting research that enabled this security work appeared last year at ISCA, but didn't fully discuss the security implications: https://www.ece.cmu.edu/~safari/pubs/kim-isca14.pdf
3.
by kmowery 12y ago
Yeah, it definitely needs to be kept secret. Since you specified that A and B can have a set-up phase before C is around, the initial setup is fairly straightforward. Depending on what the system is used for, how valuable breaking into it w
4.
by kmowery 12y ago
I'd agree. An HMAC allows A and B to send messages to each other, through C, without C being able to change or modify the message in flight. A and B just need to share the HMAC key. Handling (and changing) this key can be tricky; if an
5.
by kmowery 12y ago
That's still fairly straightforward; change the message A signs to "I trust Gamma. Nonce: whatever. Valid Until: DateTime". B should then 1) check the signature and 2) check the datetime (in that order).
6.
by kmowery 12y ago
This is covered in the Range-R FAQ: http://www.range-r.com/FAQ/index.htm The RF bands they're using apparently don't go through metal so well.
7.
by kmowery 12y ago
Sure! It's ripped + modified from a project I'm working on, so it's a little messy: http://pastebin.com/ijr3thE2
8.
by kmowery 12y ago
It does a cmp+setz, which isn't a branch (and I believe is constant-time). An x86 branch would be cmp+jne or something similar.
9.
by kmowery 12y ago
I've been writing a bunch of branch-free code recently, so I took a crack at it. In my world, data-dependent table lookups might as well be branches, so let's eliminate those as well. Here's a fizzbuzz(char*, int) function th
10.
by kmowery 12y ago
I believe they were referencing that in English it is "referrer", but has been misspelled in HTTP forever as "referer".
11.
by kmowery 12y ago
It's a little less clear than that, unfortunately. Apple chose to not support third-party Bluetooth LE dongles, which might be a reasonable engineering limitation. However, if you upgrade your Mac with a BT-LE capable board used by oth
12.
by kmowery 12y ago
No, they reproduced on "Intel (Sandy Bridge, Ivy Bridge, and Haswell) and AMD (Piledriver) systems using a 2GB DDR3 module." (see Section 4) They evict cache lines using the CLFLUSH x86 instruction, which I believe is unprivileged
13.
by kmowery 12y ago
It's not that the key is generated in Javascript; it's more that the key is generated (and therefore known) by someone who is not you. Maybe you trust StartSSL with your private key, maybe you don't, but in either case not gi
14.
by kmowery 12y ago
We don't have one of those machines to test on, so we can't say for sure. We think it's likely that they went through the same sort of evaluation process that put the Secure 1000 into service, and that they should be publicly
15.
by kmowery 12y ago
Hi! Lead author here. We'll be giving a talk on this work tomorrow at the USENIX Security, but I'm happy to answer any questions you have here before then.
16.
by kmowery 12y ago
Yes we did! Any organic material shows up pretty well under backscatter X-ray, and so can be used to cover darker contraband. You can see this done with Teflon in our gallery: https://www.radsec.org/gallery.html under &quot
17.
by kmowery 12y ago
That's correct. We think the millimeter wave machines should be looked at in a similar adversarial study, but we don't have access to one for testing.
18.
by kmowery 12y ago
You'd be surprised how difficult it was to bring it on campus and actually turn it on! Over the course of the project, we worked with our IRB, radiological safety experts, regulatory compliance, and campus public safety before we put s
19.
by kmowery 12y ago
The $1 billion number covers procurement, deployment and usage of both the Rapiscan Secure 1000 backscatter X-ray and L3 ProVision millimeter wave AIT systems. The Secure 1000s have been removed; the L3 ProVisions are still deployed in airp
20.
by kmowery 12y ago
That's correct. We have our own machine and tested it in a lab setting; we never attempted to smuggle contraband in the field.
21.
by kmowery 12y ago
Hi! Lead author here. We'll be giving a talk on this work tomorrow at the USENIX Security conference, but I'd be happy to answer questions here before then!
22.
by kmowery 12y ago
Hi! Lead author here. We only had a person in front of the X-ray scanner a few times, to minimize exposure. Most of the time we scanned a radiological "phantom", which is designed to look exactly like a human under the X-ray spect
23.
by kmowery 12y ago
As a complete derail: Floating point, as IEEE standard? Beautiful. Elegant. One of my favorite technical standards. Other than the +0/-0 thing, it's perfect. Floating point, as implemented? Ugh. You've got processors which im
24.
by kmowery 12y ago
This sort of 0-day has been known in the academic literature for some time[1]. Disclosure of critical vulnerabilities in implantable devices is far more fraught than your normal critical software 0-day. These devices require surgery for rep
25.
by kmowery 12y ago
Almost certainly repost prevention... I tried to add this article yesterday and was upvote 4 on the previous link. It just didn't get the random boost it needed to make it to the front page.
26.
by kmowery 13y ago
git commit --amend is rewriting history, just not very much of it. If you --amend after pushing, you run into the exact same problems mentioned before.