5 ms·

Doesn't this mean that if the authenticator is cracked then all of your accounts are revealed and become vulnerable? Compared to the situation today when if on

Doesn't this mean that if the authenticator is cracked then all of your accounts are revealed and become vulnerable? Compared to the situation today when if one your passwords is cracked they can't immeidately access your other accounts.

vorpalhex 8y ago
It's no worse than them breaking into a password manager, and is quite a bit better since they now have to deal with full on private keys. Most passwords are vulnerable because they are easily guessed, not because somebody breaks your encrypted password store.
Ajedi32 8y ago
Stealing Web Authentication keys from a hardware token is a significantly higher bar than phishing you or brute-forcing your password hash from a database leak. At the very _least_ the attacker would first have to compromise your machine with malware, at which point they could easily get access to all your password-protected accounts anyway with a simple keylogger.
- dmortin 8y ago
  What happens if you lose your hardware token (or it gets stolen, ec.)? Is there a way for then to access your accounts?
  - gruez 8y ago
    backup/recovery codes and/or "forgot your password (authenticator)" recovery
  - StavrosK 8y ago
    Ideally (and hopefully this will be doable, as I don't see any impediments), you can have Bitcoin-wallet-style seed generation that you can back up onto a piece of paper and store it somewhere safe. I really hope my Ledger Nano S becomes WebAuthN-compatible, as it can already be used as a U2F key.
    - tialaramex 8y ago
      Yes, for a device as complicated as the (~ $100) Ledger Nano S I don't see any reason they couldn't support that functionality. Most people will be using much cheaper, dumb authenticators which aren't going to have the capability to read and update the keys, they would be expected to replace their authenticator altogether, not try to clone it if there's a problem.
  - ethagnawl 8y ago
    This could introduce latency and centralization to the authentication process, but perhaps there could be a public key server/service that would allow the user to issue a revocation certificate. This scenario could also be a legitimate use case for blockchain technology.
    - nfoz 8y ago
      If there isn't a solution in place for revocation, then it's not really an authentication solution, IMO. I would have thought this would be part of the proposed API. Do you think it belongs there?
      - tialaramex 8y ago
        This functionality is orthogonal to the API. If say my Gmail is configured to trust my awesome Darth Vader bobble head authenticator, the tiny one I keep on my keychain and one that's in my locked desk drawer with my cyanide pills and then I lose my keys somehow, I go home, use the Darth Vader to sign in, click for the account credentials page, pick the keychain one and pick remove. I can add another one when I buy it, using the ordinary enrollment step. No new API needed or desired. The trick to U2F and this whole family of technologies is that the devices are really dumb, your authenticator doesn't remember "I'm allowed to authenticate to Google, I picked this key" it just turns google.com into a number and uses that with some crypto arithmetic. If you never actually enrolled with Google, the results are worthless but it has no idea. If I try to sign into Mike's account with Sarah's authenticator, it doesn't work but there's no clue why. The authenticator doesn't even know it's Sarah's.
tialaramex 8y ago
The authenticators are physical property of the people they authenticate. If you're especially worried you can remove it when not using it, you can lock it in a safe, you can give it to your personal bodyguard to protect with their life. Air gapped authenticators are plausible, although they'd be awful from a usability perspective, if you're really that paranoid... Whereas all your passwords are just bits, and you have to transmit those bits to a remote party every time you authenticate. You can't keep those bits safe, only trust that everybody else is looking out for you and they're all competent. Good luck with that.
ajross 8y ago
It's not a substitute for 2FA, just one of the factors. You will still need a password to authenticate new devices, etc...

vorpalhex 8y ago

It's no worse than them breaking into a password manager, and is quite a bit better since they now have to deal with full on private keys. Most passwords are vulnerable because they are easily guessed, not because somebody breaks your encrypted password store.

Ajedi32 8y ago

Stealing Web Authentication keys from a hardware token is a significantly higher bar than phishing you or brute-forcing your password hash from a database leak. At the very _least_ the attacker would first have to compromise your machine with malware, at which point they could easily get access to all your password-protected accounts anyway with a simple keylogger.

dmortin 8y ago
What happens if you lose your hardware token (or it gets stolen, ec.)? Is there a way for then to access your accounts?
- gruez 8y ago
  backup/recovery codes and/or "forgot your password (authenticator)" recovery
- StavrosK 8y ago
  Ideally (and hopefully this will be doable, as I don't see any impediments), you can have Bitcoin-wallet-style seed generation that you can back up onto a piece of paper and store it somewhere safe. I really hope my Ledger Nano S becomes WebAuthN-compatible, as it can already be used as a U2F key.
  - tialaramex 8y ago
    Yes, for a device as complicated as the (~ $100) Ledger Nano S I don't see any reason they couldn't support that functionality. Most people will be using much cheaper, dumb authenticators which aren't going to have the capability to read and update the keys, they would be expected to replace their authenticator altogether, not try to clone it if there's a problem.
- ethagnawl 8y ago
  This could introduce latency and centralization to the authentication process, but perhaps there could be a public key server/service that would allow the user to issue a revocation certificate. This scenario could also be a legitimate use case for blockchain technology.
  - nfoz 8y ago
    If there isn't a solution in place for revocation, then it's not really an authentication solution, IMO. I would have thought this would be part of the proposed API. Do you think it belongs there?
    - tialaramex 8y ago
      This functionality is orthogonal to the API. If say my Gmail is configured to trust my awesome Darth Vader bobble head authenticator, the tiny one I keep on my keychain and one that's in my locked desk drawer with my cyanide pills and then I lose my keys somehow, I go home, use the Darth Vader to sign in, click for the account credentials page, pick the keychain one and pick remove. I can add another one when I buy it, using the ordinary enrollment step. No new API needed or desired. The trick to U2F and this whole family of technologies is that the devices are really dumb, your authenticator doesn't remember "I'm allowed to authenticate to Google, I picked this key" it just turns google.com into a number and uses that with some crypto arithmetic. If you never actually enrolled with Google, the results are worthless but it has no idea. If I try to sign into Mike's account with Sarah's authenticator, it doesn't work but there's no clue why. The authenticator doesn't even know it's Sarah's.

tialaramex 8y ago

The authenticators are physical property of the people they authenticate. If you're especially worried you can remove it when not using it, you can lock it in a safe, you can give it to your personal bodyguard to protect with their life. Air gapped authenticators are plausible, although they'd be awful from a usability perspective, if you're really that paranoid... Whereas all your passwords are just bits, and you have to transmit those bits to a remote party every time you authenticate. You can't keep those bits safe, only trust that everybody else is looking out for you and they're all competent. Good luck with that.

ajross 8y ago

It's not a substitute for 2FA, just one of the factors. You will still need a password to authenticate new devices, etc...