5 ms·

BIP-39 mnemonics are designed like this, you can add an optional passphrase to the 12/24 mnemonic words and it unlocks a different set of privatekeys. This way

BIP-39 mnemonics are designed like this, you can add an optional passphrase to the 12/24 mnemonic words and it unlocks a different set of privatekeys. This way you can have a passphrase (or no passphrase) where you only store a small amount of cryptocurrency and a separate passphrase that unlocks your real wallet, to avoid the $5 wrench attack.

throwhauser 5y ago
If you're being attacked with a wrench, wouldn't you want to avoid deniable encryption? If there's no way to 100% establish that all the money has been extracted, an attacker might keep going indefinitely to see if there's more.
- littlestymaar 5y ago
  In fact, since there's no way you can prove that you haven't used deniable encryption, you'll probably be in a really bad place anyway. That creates an interesting game theory situation though, where nobody has any incentive to disclose anything, since it wouldn't change the outcome anyway, which ends up negating the whole point of torture: the victim needs to believe that the tormentor will stop if they disclose the truth. (Unfortunately, the real world isn't a game theory problem…).
  - deleted 5y ago
    [deleted]
  - dane-pgp 5y ago
    This is the game theory that the Rubberhose file system (co-invented by one Julian Assange) is based on.[0] It's a pity the blog post didn't link to that article, and only linked to the one about rubber-hose cryptanalysis, since this prior art does seem to overlap significantly with the scheme that the post is proposing, as does the Owner-Free Filesystem[1]. Anyway, you're right that the real world isn't a game theory problem, but I do think that if someone is faced with being tortured for information, they should at least attempt to ask the torturer "How do I know that you will stop when I give you the information?". Or, perhaps less incriminatingly, "I don't have that information, and it doesn't matter because you'll keep torturing me regardless". You may not be able to convince the torturer to give up on the torture (much less convince them to let you go free), but you might at least be able to convince yourself that there is no point talking or trying to come up with a lie. Having said that, it's also instructive to look at the example of Marcus McDilda who was tortured by the Japanese for information about atomic bombs, about which he knew nothing.[2] His lies may have saved not just his own life, but millions more. [0] https://en.wikipedia.org/wiki/Rubberhose_%28file_system%29 https://en.wikipedia.org/wiki/Rubberhose_%28file_system%29 [1] https://en.wikipedia.org/wiki/OFFSystem https://en.wikipedia.org/wiki/OFFSystem [2] https://en.wikipedia.org/wiki/Marcus_McDilda https://en.wikipedia.org/wiki/Marcus_McDilda
    - TimedToasts 5y ago
      > they should at least attempt to ask the torturer "How do I know that you will stop when I give you the information?" Anyone who will torture you for information is going to include this in your torture now, just fyi. Might as well just ask them to let you go.
      - dane-pgp 5y ago
        > going to include this Include what? If there's some convincing proof that the torturer can give that they will stop, I would be interested to hear it.
  - syrrim 5y ago
    You can prove you haven't used deniable encryption. Encrypted data looks random. As long as your disks and files don't contain unexplainable random sections, there must be no encrypted data there. Steganography might have been used to hide the encrypted data in otherwise meaningful data, but that is a separate concern.
    - fsflover 5y ago
      Truecrypt hidden volume looks like free space without the right password. You can't prove you don't have data there.
      - zapt02 5y ago
        That's not strictly true, you can format a drive to contain all zeroes. That can then be demonstrated easily via a hex editor looking at the drive. Truecrypt volumes will always look like random scrambled data (like if you formatted your drive with a "secure erase" method).
        Sebb767 5y ago
        Allthough this presumes that the guy with the wrench takes the time to check out your disk in a hex editor and that he finds the statement that you directly zero everything you delete to prepare for exactly this scenario not at all suspicious. Doesn't sound like a great plan to me.
hinkley 5y ago
STREET SMARTS! You need your proverbial money clip with $50 that you can throw and run when you're being mugged. STREET SMARTS!
CaptainNegative 5y ago
What I'm hearing is that I need to keep pounding that $5 wrench after they unlock their wallet in the off chance they have a second passphrase giving a larger payload.
- chordalkeyboard 5y ago
  indeed, for all such victims, naturally. and you can never be certain you've extracted the full amount. so you can never stop pounding
- TimedToasts 5y ago
  Anyone who has a second password might have a third one, better keep that arm in shape 'cause it's poundings all the way down.
  - Lio 5y ago
    The Mark “Chopper” Read method of smuggling guns into a meeting. If you hand over 3 guns at the door no one expects you to have a fourth.
  - vimax 5y ago
    Rokos crypto wrench: knowing about plausible deniability makes you more likely to be beat with a wrench.
greiskul 5y ago
That only works if your threat model is someone that is randomly mugging you. If it is a targeted wrench attack, they would already know your wallet, and the amount of funds it contains. Crypto has a lot of properties in common with cash, and for security, any large amounts that you don't plan on moving, should use more then one factor. My suggestion for extremely large amounts would be to have at least 3 factors: a password you know, a cold wallet that you have, and the third can be location: keep the cold wallet inside a secured location, with a backup of course in another secure location. And if you have family, make sure to also have plans in place if you don't want to be buried with your crypto.
- dannyw 5y ago
  Or create a 2 of 3 multisig where you control two keys, and the third key is controlled by your lawyer who is paid a retainer.

throwhauser 5y ago

If you're being attacked with a wrench, wouldn't you want to avoid deniable encryption? If there's no way to 100% establish that all the money has been extracted, an attacker might keep going indefinitely to see if there's more.

littlestymaar 5y ago
In fact, since there's no way you can prove that you haven't used deniable encryption, you'll probably be in a really bad place anyway. That creates an interesting game theory situation though, where nobody has any incentive to disclose anything, since it wouldn't change the outcome anyway, which ends up negating the whole point of torture: the victim needs to believe that the tormentor will stop if they disclose the truth. (Unfortunately, the real world isn't a game theory problem…).
- deleted 5y ago
  [deleted]
- dane-pgp 5y ago
  This is the game theory that the Rubberhose file system (co-invented by one Julian Assange) is based on.[0] It's a pity the blog post didn't link to that article, and only linked to the one about rubber-hose cryptanalysis, since this prior art does seem to overlap significantly with the scheme that the post is proposing, as does the Owner-Free Filesystem[1]. Anyway, you're right that the real world isn't a game theory problem, but I do think that if someone is faced with being tortured for information, they should at least attempt to ask the torturer "How do I know that you will stop when I give you the information?". Or, perhaps less incriminatingly, "I don't have that information, and it doesn't matter because you'll keep torturing me regardless". You may not be able to convince the torturer to give up on the torture (much less convince them to let you go free), but you might at least be able to convince yourself that there is no point talking or trying to come up with a lie. Having said that, it's also instructive to look at the example of Marcus McDilda who was tortured by the Japanese for information about atomic bombs, about which he knew nothing.[2] His lies may have saved not just his own life, but millions more. [0] https://en.wikipedia.org/wiki/Rubberhose_%28file_system%29 https://en.wikipedia.org/wiki/Rubberhose_%28file_system%29 [1] https://en.wikipedia.org/wiki/OFFSystem https://en.wikipedia.org/wiki/OFFSystem [2] https://en.wikipedia.org/wiki/Marcus_McDilda https://en.wikipedia.org/wiki/Marcus_McDilda
  - TimedToasts 5y ago
    > they should at least attempt to ask the torturer "How do I know that you will stop when I give you the information?" Anyone who will torture you for information is going to include this in your torture now, just fyi. Might as well just ask them to let you go.
    - dane-pgp 5y ago
      > going to include this Include what? If there's some convincing proof that the torturer can give that they will stop, I would be interested to hear it.
- syrrim 5y ago
  You can prove you haven't used deniable encryption. Encrypted data looks random. As long as your disks and files don't contain unexplainable random sections, there must be no encrypted data there. Steganography might have been used to hide the encrypted data in otherwise meaningful data, but that is a separate concern.
  - fsflover 5y ago
    Truecrypt hidden volume looks like free space without the right password. You can't prove you don't have data there.
    - zapt02 5y ago
      That's not strictly true, you can format a drive to contain all zeroes. That can then be demonstrated easily via a hex editor looking at the drive. Truecrypt volumes will always look like random scrambled data (like if you formatted your drive with a "secure erase" method).
      - Sebb767 5y ago
        Allthough this presumes that the guy with the wrench takes the time to check out your disk in a hex editor and that he finds the statement that you directly zero everything you delete to prepare for exactly this scenario not at all suspicious. Doesn't sound like a great plan to me.

hinkley 5y ago

STREET SMARTS! You need your proverbial money clip with $50 that you can throw and run when you're being mugged. STREET SMARTS!

CaptainNegative 5y ago

What I'm hearing is that I need to keep pounding that $5 wrench after they unlock their wallet in the off chance they have a second passphrase giving a larger payload.

chordalkeyboard 5y ago
indeed, for all such victims, naturally. and you can never be certain you've extracted the full amount. so you can never stop pounding
TimedToasts 5y ago
Anyone who has a second password might have a third one, better keep that arm in shape 'cause it's poundings all the way down.
- Lio 5y ago
  The Mark “Chopper” Read method of smuggling guns into a meeting. If you hand over 3 guns at the door no one expects you to have a fourth.
- vimax 5y ago
  Rokos crypto wrench: knowing about plausible deniability makes you more likely to be beat with a wrench.

greiskul 5y ago

That only works if your threat model is someone that is randomly mugging you. If it is a targeted wrench attack, they would already know your wallet, and the amount of funds it contains. Crypto has a lot of properties in common with cash, and for security, any large amounts that you don't plan on moving, should use more then one factor. My suggestion for extremely large amounts would be to have at least 3 factors: a password you know, a cold wallet that you have, and the third can be location: keep the cold wallet inside a secured location, with a backup of course in another secure location. And if you have family, make sure to also have plans in place if you don't want to be buried with your crypto.

dannyw 5y ago
Or create a 2 of 3 multisig where you control two keys, and the third key is controlled by your lawyer who is paid a retainer.