WTF is a KDF? • Hacker News Board

Re: WTF is a KDF?

#51

Post by motohagiography » Sun, Apr 23, 2023, 1:21 PM UTC

While I haven't worked on LUKS, if you put aside using several millions of dollars in raw compute, the options are in order of likelihood:

- recovering the key from a deleted file, ram, or other caches.

- obtained key or bytes thereof by prior surveillance. (so many ways)

- a forensics company could be sitting on a LUKS zero-day the way certain companies sit on Signal and iPhone vulns and use them on behalf of state actors.

- exploited a deprecated version themselves with an implementation error.

- prisoner had a short key because he used it so often

- brute force using generated wordlists from surveillance and data transcripts.

- trained a GPT model on all the books, music and online forum posts the prisoner had ever bought and used and produced a weighted wordlist. (I just made that one up.)

- Happen to have "millions of dollars in gpu time" because they already had racks of seized mining rigs from other investigations so the main cost was electricity.

Being an anarchist or secret police in France just seems like participation in their national traditions of riot sports, intrigue, and feats of mysterious intellectual prowess. There are so many unanswered questions in the story, I will wait for the Wes Anderson adaptation before thinking about it again.

Re: WTF is a KDF?

#52

Post by Closi » Sun, Apr 23, 2023, 1:22 PM UTC

flangola7 wrote: post #50

Closi wrote: post #47

"An activist imprisoned in France" makes this sound like some sort of locked up protestor, rather than someone that set fire to a load of vehicles and a warehouse. It should really read "An arsonist imprisoned in France".

Those aren't mutually exclusive. France isn't known for having neutered nonviolent protests like those in the US and UK.

It's true, but if a murderer that donated to charity was imprisoned I would probably go with "a murderer imprisoned in France" rather than "a philanthropist imprisoned in France".

Re: WTF is a KDF?

#53

Post by CoastalCoder » Sun, Apr 23, 2023, 1:22 PM UTC

Closi wrote: post #47

"An activist imprisoned in France" makes this sound like some sort of locked up protestor, rather than someone that set fire to a load of vehicles and a warehouse. It should really read "An arsonist imprisoned in France".

Interesting point. One word seems to bias us toward sympathetic assumptions, and the other away from them.

I'm struggling to think of a good neutral term for this case.

Re: WTF is a KDF?

#54

Post by justinclift » Sun, Apr 23, 2023, 1:23 PM UTC

Closi wrote: post #47

"An activist imprisoned in France" makes this sound like some sort of locked up protestor, rather than someone that set fire to a load of vehicles and a warehouse. It should really read "An arsonist imprisoned in France".

Aren't they just "accused of arson" at this point?

Re: WTF is a KDF?

#55

Post by le-mark » Sun, Apr 23, 2023, 1:24 PM UTC

marginalia_nu wrote: post #27

WastingMyTime89 wrote: post #10

Earlier quoted context omitted.

Multiple possible scenarios: - He actually gave his password himself as part of a deal with the police which includes this as a cover up. - The police got his password through another mean they don’t want to disclose and are using this as a cover up. - They really want a list of his contacts and what they were discussing because they are scared than one of them could be tempted to do more than burn a few cars. - Fran…

If I wanted to get at an encrypted hard drive, I'd just tamper with the keyboard and record the password as it was being typed. Hardware keyloggers can be made very tiny with resources and determination.

Does anyone have information or experience with this?

Re: WTF is a KDF?

#56

Post by Snawoot » Sun, Apr 23, 2023, 1:34 PM UTC

Bruteforce of such random password is just not plausible and talks about KDF "weakness" is just a distraction. I think most likely it was evil maid attack.

Here are projects which try to mitigate some of evil maid attack risks:

https://github.com/noahbliss/mortar

https://safeboot.dev/

Re: WTF is a KDF?

#57

Post by wood_spirit » Sun, Apr 23, 2023, 1:38 PM UTC

motohagiography wrote: post #51

While I haven't worked on LUKS, if you put aside using several millions of dollars in raw compute, the options are in order of likelihood: - recovering the key from a deleted file, ram, or other caches. - obtained key or bytes thereof by prior surveillance. (so many ways) - a forensics company could be sitting on a LUKS zero-day the way certain companies sit on Signal and iPhone vulns and use them on behalf of state…

Also, I would expect the government can crack passwords more cheaply than hiring normal commercial cloud compute.

Everything from negotiating good prices, to having their own or reserved cloud so the cost is having the ability to do it more than actually doing each crack, to asking an ally for help.

Would be kinda shocking if they pay the sticker price for this stuff.

Re: WTF is a KDF?

#58

Post by kebman » Sun, Apr 23, 2023, 1:41 PM UTC

Closi wrote: post #47

"An activist imprisoned in France" makes this sound like some sort of locked up protestor, rather than someone that set fire to a load of vehicles and a warehouse. It should really read "An arsonist imprisoned in France".

If you look into Koba's life before he came Stalin; even if you try to give what he did neutral descriptions, the words "mafia racket" still comes to mind.

Re: WTF is a KDF?

#59

Post by Brian_K_White » Sun, Apr 23, 2023, 1:59 PM UTC

upofadown wrote: post #44

An interesting bit from the linked ElcomSoft article: >Brute force attacks became not just faster, but much smarter as well. The user’s existing passwords are an excellent starting point. These passwords can be pulled from the user’s Google Account, macOS, iOS or iCloud keychain, Microsoft Account, or simply extracted from the user’s computer. The user’s existing passwords give a hint at what character groups are lik…

Not just subsets/supersets, but similar concepts and patterns.

Re: WTF is a KDF?

#60

Post by alsobrsp » Sun, Apr 23, 2023, 2:13 PM UTC

mr_mitm wrote: post #13

It really annoys me how everyone takes that statement that a 20 character password has been cracked at face value. If it was randomly generated, it is physically impossible to crack even if it was hashed with MD5. It's also unlikely that somebody memorized 20 random characters. It is much more likely that the passphrase was weak because it's the title of a Wikipedia article or contained in some public word list. Also…

> It's also unlikely that somebody memorized 20 random characters.

I routinely memorized 15 character random passwords until I switched to bitwarden, 20 doesn't seem out of bounds. Now, with bitwarden, I have no idea what any of my passwords are.