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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 physicall

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, by going with the original article (https://nantes.indymedia.org/posts/87395/une-lettre-divan-enferme-a-la-prison-de-villepinte-perquisitions-et-disques-durs-dechiffres/ https://nantes.indymedia.org/posts/87395/une-lettre-divan-en...), which I translated using DeepL, this is what we know: > As far as the investigation is concerned, in recent months new elements have been added to the file. The most significant is that the police managed to gain access to my computers, even though they were encrypted. The one at work, on which Windows is installed, is encrypted with BitLocker. _A previous report in the file says that they had already tried to access it while I was in police custody but had not succeeded._ But in September the Brigade d'appui en téléphonie, cyber-investigation et analyse criminelle (BATCIAC) sent a copy of the hard disk to the SDAT. In the PV, they only explain that they booted the computer with a bootable USB key and then used the software AccesData FTK imager 3.3.05 to copy the hard disk. But they don't talk about the decryption itself. > My personal computer, which runs Ubuntu 18, is encrypted with Luks (the password is more than twenty characters: letters, numbers, punctuation marks...). I couldn't find any indication in the file about how they decrypted it, but there too they made a copy of the hard disk. There are even files that had been deleted and emails that had been downloaded with Thunderbird (and then deleted). They didn't find anything that could be related to the fires I'm charged with. But I think the very fact that they were able to access hard drives encrypted with supposedly unbreakable software should be made as widely known as possible. This clearly hints at an evil maid attack, which we always knew were a real risk when it comes to full disk encryption.

st_goliath 4y ago
Thanks! Reading the article, I was already wondering myself: Do we already know any of this for fact, or is this just more wild mass guessing? The article doesn't seem to cite any new sources other than people speculating on twitter/mastodon. Following down the social media rabbit hole, I end up back at the article that sparked the debate 5 days ago. Some RFCs and product data sheets are cited to support the back-on-the-napkin calculations (also cited from social media), but do we have any credible source yet to confirm that's what really happened here?
jeroenhd 4y ago
Until we know his password, we can't know for certain. "Fuck the police!2023" fits the description of the password but it's hardly unguessable. All we know is the authorities gained access to his drive's key. We probably won't find out how they did it until his trial starts.
- mr_mitm 4y ago
  Well, we also know they didn't crack a random 20 character password. But some people appear to be panicking as if they did.
  - Aeolun 4y ago
    You know this because you think it is mathematically impossible?
    - mr_mitm 4y ago
      Not mathematically, but physically. You need astronomical quantities of energy. Bruce Schneier pointed this out in "Applied Cryptography" (1996): https://www.schneier.com/blog/archives/2009/09/the_doghouse_cr.html https://www.schneier.com/blog/archives/2009/09/the_doghouse_... (unfortunately the exponents are not displayed correctly here) > One of the consequences of the second law of thermodynamics is that a certain amount of energy is necessary to represent information. To record a single bit by changing the state of a system requires an amount of energy no less than kT, where T is the absolute temperature of the system and k is the Boltzman constant. (Stick with me; the physics lesson is almost over.) >Given that k = 1.38×10-16 erg/°Kelvin, and that the ambient temperature of the universe is 3.2°Kelvin, an ideal computer running at 3.2°K would consume 4.4×10-16 ergs every time it set or cleared a bit. To run a computer any colder than the cosmic background radiation would require extra energy to run a heat pump. >Now, the annual energy output of our sun is about 1.21×1041 ergs. This is enough to power about 2.7×1056 single bit changes on our ideal computer; enough state changes to put a 187-bit counter through all its values. If we built a Dyson sphere around the sun and captured all its energy for 32 years, without any loss, we could power a computer to count up to 2192. Of course, it wouldn’t have the energy left over to perform any useful calculations with this counter. >But that’s just one star, and a measly one at that. A typical supernova releases something like 1051 ergs. (About a hundred times as much energy would be released in the form of neutrinos, but let them go for now.) If all of this energy could be channeled into a single orgy of computation, a 219-bit counter could be cycled through all of its states. >These numbers have nothing to do with the technology of the devices; they are the maximums that thermodynamics will allow. And they strongly imply that brute-force attacks against 256-bit keys will be infeasible until computers are built from something other than matter and occupy something other than space.
dist-epoch 4y ago
Why would they do an evil maid attack on the Ubuntu laptop, but not at the same time on the Windows one? And is there any information that they accessed the Ubuntu laptop before he was arrested (to do the evil maid attack)? I see no mention of that. I think it's much more likely that it was a weak password, maybe even partially shared with other passwords. Maybe police obtained user passwords from other low value targets (online shops, ...), looked at them and noticed a pattern. > There are even files that had been deleted and emails that had been downloaded with Thunderbird (and then deleted). This doesn't mean much, unless user didn't know that when you delete a file it's content is not actually scrubbed from storage.
lapinot 4y ago
I agree with taking this with a grain of salt, but i'm not sure how "this clearly hints at an evil maid attack". At this point anything is pure speculation: evil maid or other pre-seizure compromise, some amount of password guessing, exploit in some of the software, secret extraction from hardware, ...
rhplus 4y ago
He says his BitLocker drive was on a work computer. If it was managed through Active Directory then those key may have been recoverable through his employer. https://learn.microsoft.com/en-us/windows/security/information-protection/bitlocker/bitlocker-recovery-guide-plan https://learn.microsoft.com/en-us/windows/security/informati...
- Beldin 4y ago
  There used to be a bug where bitlocker would rely on the firmware's encryption functionality if it was there, and there were cases of firmware with a literal "if checkpasswd () then"... overwrite that check to true and you're in. Soif it concerned a disk with that vulnerability, maybe they did it like that. (See https://www.ieee-security.org/TC/SP2019/papers/310.pdf https://www.ieee-security.org/TC/SP2019/papers/310.pdf)
- WhereIsTheTruth 4y ago
  Little backdoors
alsobrsp 4y ago
> 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.
- septune 4y ago
  I did this too, now i generate a random pwd long as hell and i do a pwd recovery when i have to log-in so i don’t have to store them anywhere. My master pwd is my email pwd based on a mail server i operate. Yes paranoid is my second name.
- jadtz 4y ago
  So now you only memorize one 15 character random password for your bitwarden, is this the way to go? I am new to password managers.
  - mock-possum 4y ago
    That’s the idea yeah - you have one long high entropy password that you use to unlock all your others. Then you only need to remember one thing. In my case, this isn’t my literal password, but it’s very similar to: “These420HugeWhiteBadgers1984” Which is secure enough, easy to enter, and easy to remember.
eternalban 4y ago
> even if it was hashed with MD5 This is what I don't understand about articles like this. Say we're using a cryptographic hash to generate the password from even a commonplace phrase. Typically you will have thousands of random bits in the hash and you can grab a uint64 (or even a uint128 if you want) from anywhere in that (theoretically uniformly distributed) set of bits. Is that not a random point in a 2^64 (2^128) space?
- rlpb 4y ago
  No, because in that entire space, only eg. 62^20 would be used, and that's a much smaller space. There are various techniques to focus on that subset of the space.
deleted 4y ago
[deleted]
matheusmoreira 4y ago
> the password is more than twenty characters: letters, numbers, punctuation marks Was it random, though?

st_goliath 4y ago

Thanks! Reading the article, I was already wondering myself: Do we already know any of this for fact, or is this just more wild mass guessing? The article doesn't seem to cite any new sources other than people speculating on twitter/mastodon. Following down the social media rabbit hole, I end up back at the article that sparked the debate 5 days ago. Some RFCs and product data sheets are cited to support the back-on-the-napkin calculations (also cited from social media), but do we have any credible source yet to confirm that's what really happened here?

jeroenhd 4y ago

Until we know his password, we can't know for certain. "Fuck the police!2023" fits the description of the password but it's hardly unguessable. All we know is the authorities gained access to his drive's key. We probably won't find out how they did it until his trial starts.

mr_mitm 4y ago
Well, we also know they didn't crack a random 20 character password. But some people appear to be panicking as if they did.
- Aeolun 4y ago
  You know this because you think it is mathematically impossible?
  - mr_mitm 4y ago
    Not mathematically, but physically. You need astronomical quantities of energy. Bruce Schneier pointed this out in "Applied Cryptography" (1996): https://www.schneier.com/blog/archives/2009/09/the_doghouse_cr.html https://www.schneier.com/blog/archives/2009/09/the_doghouse_... (unfortunately the exponents are not displayed correctly here) > One of the consequences of the second law of thermodynamics is that a certain amount of energy is necessary to represent information. To record a single bit by changing the state of a system requires an amount of energy no less than kT, where T is the absolute temperature of the system and k is the Boltzman constant. (Stick with me; the physics lesson is almost over.) >Given that k = 1.38×10-16 erg/°Kelvin, and that the ambient temperature of the universe is 3.2°Kelvin, an ideal computer running at 3.2°K would consume 4.4×10-16 ergs every time it set or cleared a bit. To run a computer any colder than the cosmic background radiation would require extra energy to run a heat pump. >Now, the annual energy output of our sun is about 1.21×1041 ergs. This is enough to power about 2.7×1056 single bit changes on our ideal computer; enough state changes to put a 187-bit counter through all its values. If we built a Dyson sphere around the sun and captured all its energy for 32 years, without any loss, we could power a computer to count up to 2192. Of course, it wouldn’t have the energy left over to perform any useful calculations with this counter. >But that’s just one star, and a measly one at that. A typical supernova releases something like 1051 ergs. (About a hundred times as much energy would be released in the form of neutrinos, but let them go for now.) If all of this energy could be channeled into a single orgy of computation, a 219-bit counter could be cycled through all of its states. >These numbers have nothing to do with the technology of the devices; they are the maximums that thermodynamics will allow. And they strongly imply that brute-force attacks against 256-bit keys will be infeasible until computers are built from something other than matter and occupy something other than space.

dist-epoch 4y ago

Why would they do an evil maid attack on the Ubuntu laptop, but not at the same time on the Windows one? And is there any information that they accessed the Ubuntu laptop before he was arrested (to do the evil maid attack)? I see no mention of that. I think it's much more likely that it was a weak password, maybe even partially shared with other passwords. Maybe police obtained user passwords from other low value targets (online shops, ...), looked at them and noticed a pattern. > There are even files that had been deleted and emails that had been downloaded with Thunderbird (and then deleted). This doesn't mean much, unless user didn't know that when you delete a file it's content is not actually scrubbed from storage.

lapinot 4y ago

I agree with taking this with a grain of salt, but i'm not sure how "this clearly hints at an evil maid attack". At this point anything is pure speculation: evil maid or other pre-seizure compromise, some amount of password guessing, exploit in some of the software, secret extraction from hardware, ...

rhplus 4y ago

He says his BitLocker drive was on a work computer. If it was managed through Active Directory then those key may have been recoverable through his employer. https://learn.microsoft.com/en-us/windows/security/information-protection/bitlocker/bitlocker-recovery-guide-plan https://learn.microsoft.com/en-us/windows/security/informati...

Beldin 4y ago
There used to be a bug where bitlocker would rely on the firmware's encryption functionality if it was there, and there were cases of firmware with a literal "if checkpasswd () then"... overwrite that check to true and you're in. Soif it concerned a disk with that vulnerability, maybe they did it like that. (See https://www.ieee-security.org/TC/SP2019/papers/310.pdf https://www.ieee-security.org/TC/SP2019/papers/310.pdf)
WhereIsTheTruth 4y ago
Little backdoors

alsobrsp 4y ago

> 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.

septune 4y ago
I did this too, now i generate a random pwd long as hell and i do a pwd recovery when i have to log-in so i don’t have to store them anywhere. My master pwd is my email pwd based on a mail server i operate. Yes paranoid is my second name.
jadtz 4y ago
So now you only memorize one 15 character random password for your bitwarden, is this the way to go? I am new to password managers.
- mock-possum 4y ago
  That’s the idea yeah - you have one long high entropy password that you use to unlock all your others. Then you only need to remember one thing. In my case, this isn’t my literal password, but it’s very similar to: “These420HugeWhiteBadgers1984” Which is secure enough, easy to enter, and easy to remember.

eternalban 4y ago

> even if it was hashed with MD5 This is what I don't understand about articles like this. Say we're using a cryptographic hash to generate the password from even a commonplace phrase. Typically you will have thousands of random bits in the hash and you can grab a uint64 (or even a uint128 if you want) from anywhere in that (theoretically uniformly distributed) set of bits. Is that not a random point in a 2^64 (2^128) space?

rlpb 4y ago
No, because in that entire space, only eg. 62^20 would be used, and that's a much smaller space. There are various techniques to focus on that subset of the space.

deleted 4y ago

[deleted]

matheusmoreira 4y ago

> the password is more than twenty characters: letters, numbers, punctuation marks Was it random, though?