The Side Channel

5:36 AM

@bdegnan Having the data and the key be the same, no. But different data for each key, yes, it makes a big difference.

@bdegnan If everyone used the same data but different keys, a multi-target attack on the first of t targets would reduce the cost by a factor of t over a single-target attack. But if everyone uses unique data, that advantage goes away.

5:56 AM

@bdegnan Now, why the crypt code puts salt and the password in the block to be encrypted, rather than just putting the salt in there, I don't know. Curiously, Morris–Thompson describes going directly from E_pw(constant) to E_pw(pw || salt); also curiously, the actual code I have handy uses E_pw(const, salt) where salt is a separate parameter that modifies DES itself.

5 hours later…

11:18 AM

@SqueamishOssifrage Thanks. Trying to get into someone's head from 30 years ago is awkward.

2 hours later…

1:31 PM

@bdegnan Closest you'll get past the comments, short of asking the authors, is probably Robert Morris and Ken Thompson, ‘Password Security: A Case History’, Communications of the ACM 22(11), 1979, pp. 594–597.

2 hours later…

Maarten Bodewes

3:54 PM

I've survived the Raz for two times more and am back.

Nice waves, a bit choppy.

Anything interesting happened during my holidays? Or was it just the turning of the wheels (after a key press, apparently)?

4:25 PM

@SqueamishOssifrage thanks! (jebus man, you've read just about everything)

1 hour later…

5:29 PM

I have not read just about everything, and stop calling me Jesus!

Patriot

5:40 PM

@ Forest OK, thank you again. I admit that I did not know about the market being crowded. When I go public with it, one way or another, I'll write you an email. Any comments from you will be much appreciated.

Is there any credible evidence we can bring to bear on the question of whether SHA1 has been inverted?

There is no credible evidence of preimage attacks on SHA-1.

@Patriot You cannot invert a hash per se, as it is lossy. There are not preimage attacks on SHA-1 that I know of

... and Squeamish beats me to the punch

Lots of ‘hashes’ can be inverted. (Not necessarily uniquely, of course!)

@SqueamishOssifrage what's the nuance there? I look at hashes as lossy compression, so regarding inverting them, you are referring to just running them backwards algorithmically?

For example, it is easy to find, given a key and a hash, a message that hashes to that hash under that key with Poly1305.

It is easy to find, given a hash, a message that hashes to that hash under 2-pass Snefru.

There may be many such messages for that particular hash, of course—hence not unique.

5:55 PM

ah, I see.

Patriot

I worry that the OpenPGP Standard is much more open than most think, but it is just a hunch. They could replace SHA-1 in the MDC packet, but they won't. Backwards compatibility could be an option instead of a default.

@Patriot but then the average end user's app breaks and they will switch to something that works (albeit insecurely)

Patriot

@ SEJPM Yes, I see. I worry that SHA-1 is just a lock that the fox gave the chickens to protect the chicken coop.

I'll shut up now.

3 hours later…

DannyNiu

9:13 PM

Japanese scientists announced the first fully controlled 1024 qubit quantum computer operating at -300 degrees Celsius, running the Harmonics Oscillating Accelerated Computing System (HOACS)

@DannyNiu 1024 physical qubits?

Maarten Bodewes

Yipes, that's a lot of qubits, if they are interconnected anyway.

Could you link to the announcement? I cannot find it...

Running at 26.85 kelvins below absolute zero?

@SqueamishOssifrage that's quite warm, isn't it?

DannyNiu

Guys! The operating system is HOACS!

And the operating temperature is below absolute zero!

9:22 PM

ohh

I thought it was 26.85 above absolute zero...

DannyNiu

I wrote the joke in Chinese, if anyone's interested. bilibili.com/read/cv2876817

And the physical partical is "graviton".

Maarten Bodewes

D'oh. That's what you get after 10 hours in a car.

Brain is mush'

Graviton

In theories of quantum gravity, the graviton is the hypothetical quantum of gravity, an elementary particle that mediates the force of gravity. There is no complete quantum field theory of gravitons due to an outstanding mathematical problem with renormalization in general relativity. In string theory, believed to be a consistent theory of quantum gravity, the graviton is a massless state of a fundamental string. If it exists, the graviton is expected to be massless because the gravitational force is very long range and appears to propagate at the speed of light. The graviton must be a spin-2 boson...

so graviton is a thing

@DannyNiu english google translate version

bing translated version

whyyyyyyyyyyyyyy has the plague of the red dot befallen me

@SqueamishOssifrage because apparently not enough people visit the close vote review queue?

9:36 PM

it is empty

BUT I AM STILL DOTTED WITH RED

@SqueamishOssifrage refresh your page then

I refreshed but the red dot keeps coming back. It has been plaguing for a week.

@SqueamishOssifrage file a bug on Meta Stack Exchange then?

What, you mean like lifting a finger to solve the problem instead of kvetching?

Q: Examples of protocols that are insecure when run concurrently

@SqueamishOssifrage yes

Crypto HNQ

9:50 PM

I was reading Canetti00 Universally Composable security paper. The first page of introduction says that there are some MPC protocols and Zero knowledge protocols that are insecure under concurrent composition. I don't see why protocols might break when concurrently composed together. Please pro...