robryk @robryk@social.cleverlibre.org

Look at the construction (and the proof in appendix) of public key encryption scheme out of witness encryption in https://eprint.iacr.org/2013/258.pdf

It uses witness encryption, where the only confidentiality guarantee is that "if you encrypt the plaintext in a way that does not admit decryption at all, there will be no way to recover the plaintext from ciphertext", to construct something that actually has standardish confidentiality guarantees by exploiting that this property must extend to cases that are computationally indistinguishable from ones where the assumption really holds.

#cryptography

TIL about https://en.wikipedia.org/wiki/Helium_hydride_ion

Rereading a novel I got amused by:

> Wanaka’s rather grim smile could just be made out behind her mask. “Until we get a better idea,” she
gestured. “All hands, start thinking.”

Hm~ thought experiment: how would the world look like if trademarks could only be owned by corporations[1] with a responsibility only towards upholding the trademark's reputation[2]?

[1] question of ownership unresolved (theoretically it should be immaterial)

[2] question of who has standing to argue that they're not fulfilling this duty also open

cc @TechConnectify @aredridel

We define the rank of a matrix as the minimal number of rank-1 (i.e. of the form w^\dagger{}v) matrices that sum to it. I wonder what happens when we decide to optimize for something else: say, norm of type $foo over norms of type $bar over those matrices. Obvious candidates for $foo are L_{something}, for $bar are operator norms or Frobenius norm.

In particular, $foo=L_n and $bar=operator norm inherited from L_n seems potentially interesting (in particular for n=2).

#linearalgebra

Ok, it seems to have the the old-and-well-known preponderance to just pull numbers and multiply them without regard for what they are: https://you.com/search?q=How+heavy+is+1l+of+air+at+10atm%3F&fromSearchBar=true&tbm=youchat

The chatbot-style answers of https://you.com seem impressive.

If asked nonsensical questions, they provide nonsensical answers. However, contrary to chatgpt, when asked very weird but sensible questions or fact lookup questions, it does provide correct answers (also, doesn't refuse to answer questions on fake grounds).

How do client blacklists work with gdpr?

@kuba

Why do PKP IC (https://www.pkp.pl/) and Blik (https://blik.com/en) put people under time pressure when performing transactions? They teach people to click stuff without reading (and probably also lose some part of ability to claim that customers really know the terms of service, given that they make them impossible to read in the timeframe).

When you don't realize that you've bought disks with quite high vibrations at seek time:

(The doohickeys are from https://www.thingiverse.com/thing:1774380. All in all works surprisingly well; apparently ~all the audible seek noise was coming via the case due to impedance matching.)