5 ms·

I've always hated that I couldn't clone or backup my personal yubikey. It's one of the reasons I've avoided using it everywhere.

kyrra 2y ago
I mean, that's the security story around it. You solve this and buying multiple yubikeys. Google and others support multiple keys, which gives you the backup story (I have 4 keys in various places).
- jzig 2y ago
  You register 4 keys on each website?
  - fragmede 2y ago
    I mean, not all at once, but (I only have 3) there's the one when I bought a new laptop in 2019 which I setup when I got that laptop and became the old one when I got a new laptop in 2021 and setup a second one. And then the third one is a backup key I made at some point and is stored offsite in case I/my house gets robbed/burgled or my place burns down in a fire. It's inconvenient, sure, but it's more convenient than my bank accounts that are accessible online being cleaned out.
  - michaelt 2y ago
    You register multiple keys on a handful of critically important websites. Password manager. Primary e-mail account. DNS provider. Other than that, it's rarely supported and rarely worth the hassle when it is.
    - brendoelfrendo 2y ago
      It is really annoying that more sites don't support multiple security keys, though. As far as I can tell, it's not encouraged by the FIDO Alliance and I can't think of a good technical reason for it.
      - vel0city 2y ago
        The vast majority of sites I've used Yubikeys for have supported multiple. About the only one that I use which still doesn't to my knowledge is Paypal.
        brendoelfrendo 2y ago
        Maybe I'm out of date, then! I don't enroll new keys very often. Paypal is a great example of a service that I would like to support multiple keys, though, so it's disappointing that they still only support one.
      - fullstop 2y ago
        I forget which financial institution I was using at the time, but they explicitly only supported one key. That is, you add a new one and the old one is expunged. Banks are so slow with this sort of thing, and still require SMS as a fallback option.
      - beezle 2y ago
        How often do you check to see that those other/backup keys are still secure? This attack becomes easier if the attacker knows of the secondary key(s) location and because of disuse they aren't even necessary to replace.
  - DANmode 2y ago
    If you have a hardware key setup for anything you want sustainably operated in the future, you register at least two keys, and when one fails or is lost, you pull the emergency backup out of a safe and register new one(s).
    - nicolas_17 2y ago
      You also have to pull the emergency backup out of the safe when signing up for a new thing. It's highly inconvenient.
      - throwaway48476 2y ago
        Still more convenient than getting locked out.
        drdaeman 2y ago
        It becomes questionable if you’re halfway across the world from your safe.
        lxgr 2y ago
        True, but what's even more convenient than that is to just not use hardware authenticators for anything but the most important accounts/sites, and e.g. use syncing credentials (as provided by many password managers, Google, and Apple). The fraction of people willing to regularly schedule enroll-o-ramas at each of their accounts and each of their backup key locations is probably smaller than a percent of all potential WebAuthN users.
- deleted 2y ago
  [deleted]
- lxgr 2y ago
  There's no fundamental reason it needs to be this difficult. Yubico or really any other manufacturer could totally e.g. release "Yubikey pairs", both a stateless CTAP2 implementation with the same root secret, that would correspondingly work at the same sites without having to synchronize anything. The reason they probably don't is that their entire trust model heavily depends on the perception that nobody, including the manufacturer, has a "reserve key" to any given Yubikey, even though of course the absence of such "linked keys" doesn't demonstrate the absence of any such backdoor. To be clear, I don't have any reason to believe Yubico does this, but it would probably be a harder story to tell, marketing-wise, if they sometimes selectively did, even if it's for a valid use case.
  - filleokus 2y ago
    I mean you could also design keys to be synchronisable by the user. Generate a key-pair inside of key (2), transfer the public key from (2) to (1). Encrypt the the root key inside of (1) with the public key, transfer it over to (2). (Or just allow the user to generate the root key outside of the device and insert it) I honestly think the interest from customers is just too low. I would bet the majority of Yubico's customers are enterprises where this is not really an issue for most use cases. If you loose your key used for Entra ID / SSO, just go to IT support and get a new one enrolled to your account. Much cheaper than having synchronised hot spares (at 30-50 USD a pop) for thousands of employees.
    - KAMSPioneer 2y ago
      But what stops Mallory from simply using this sync method to sync your private key to her Yubikey? I mean, look at the kerfuffle that's been kicked up by this vulnerability, and a key-sharing scheme like the above is much easier to exploit. (The second idea seems better assuming the user nukes the private key once the import is done. Otherwise the weakest link in the security chain will continue to be the opsec you practice with the private key file, in which case why spend the money on the Yubikey?)
      - filleokus 2y ago
thadt 2y ago
Good news then, since the article is discussing the discovery of that exact feature.

kyrra 2y ago

I mean, that's the security story around it. You solve this and buying multiple yubikeys. Google and others support multiple keys, which gives you the backup story (I have 4 keys in various places).

jzig 2y ago
You register 4 keys on each website?
- fragmede 2y ago
  I mean, not all at once, but (I only have 3) there's the one when I bought a new laptop in 2019 which I setup when I got that laptop and became the old one when I got a new laptop in 2021 and setup a second one. And then the third one is a backup key I made at some point and is stored offsite in case I/my house gets robbed/burgled or my place burns down in a fire. It's inconvenient, sure, but it's more convenient than my bank accounts that are accessible online being cleaned out.
- michaelt 2y ago
  You register multiple keys on a handful of critically important websites. Password manager. Primary e-mail account. DNS provider. Other than that, it's rarely supported and rarely worth the hassle when it is.
  - brendoelfrendo 2y ago
    It is really annoying that more sites don't support multiple security keys, though. As far as I can tell, it's not encouraged by the FIDO Alliance and I can't think of a good technical reason for it.
    - vel0city 2y ago
      The vast majority of sites I've used Yubikeys for have supported multiple. About the only one that I use which still doesn't to my knowledge is Paypal.
      - brendoelfrendo 2y ago
        Maybe I'm out of date, then! I don't enroll new keys very often. Paypal is a great example of a service that I would like to support multiple keys, though, so it's disappointing that they still only support one.
    - fullstop 2y ago
      I forget which financial institution I was using at the time, but they explicitly only supported one key. That is, you add a new one and the old one is expunged. Banks are so slow with this sort of thing, and still require SMS as a fallback option.
    - beezle 2y ago
      How often do you check to see that those other/backup keys are still secure? This attack becomes easier if the attacker knows of the secondary key(s) location and because of disuse they aren't even necessary to replace.
- DANmode 2y ago
  If you have a hardware key setup for anything you want sustainably operated in the future, you register at least two keys, and when one fails or is lost, you pull the emergency backup out of a safe and register new one(s).
  - nicolas_17 2y ago
    You also have to pull the emergency backup out of the safe when signing up for a new thing. It's highly inconvenient.
    - throwaway48476 2y ago
      Still more convenient than getting locked out.
      - drdaeman 2y ago
        It becomes questionable if you’re halfway across the world from your safe.
      - lxgr 2y ago
        True, but what's even more convenient than that is to just not use hardware authenticators for anything but the most important accounts/sites, and e.g. use syncing credentials (as provided by many password managers, Google, and Apple). The fraction of people willing to regularly schedule enroll-o-ramas at each of their accounts and each of their backup key locations is probably smaller than a percent of all potential WebAuthN users.
deleted 2y ago
[deleted]
lxgr 2y ago
There's no fundamental reason it needs to be this difficult. Yubico or really any other manufacturer could totally e.g. release "Yubikey pairs", both a stateless CTAP2 implementation with the same root secret, that would correspondingly work at the same sites without having to synchronize anything. The reason they probably don't is that their entire trust model heavily depends on the perception that nobody, including the manufacturer, has a "reserve key" to any given Yubikey, even though of course the absence of such "linked keys" doesn't demonstrate the absence of any such backdoor. To be clear, I don't have any reason to believe Yubico does this, but it would probably be a harder story to tell, marketing-wise, if they sometimes selectively did, even if it's for a valid use case.
- filleokus 2y ago
  I mean you could also design keys to be synchronisable by the user. Generate a key-pair inside of key (2), transfer the public key from (2) to (1). Encrypt the the root key inside of (1) with the public key, transfer it over to (2). (Or just allow the user to generate the root key outside of the device and insert it) I honestly think the interest from customers is just too low. I would bet the majority of Yubico's customers are enterprises where this is not really an issue for most use cases. If you loose your key used for Entra ID / SSO, just go to IT support and get a new one enrolled to your account. Much cheaper than having synchronised hot spares (at 30-50 USD a pop) for thousands of employees.
  - KAMSPioneer 2y ago
    But what stops Mallory from simply using this sync method to sync your private key to her Yubikey? I mean, look at the kerfuffle that's been kicked up by this vulnerability, and a key-sharing scheme like the above is much easier to exploit. (The second idea seems better assuming the user nukes the private key once the import is done. Otherwise the weakest link in the security chain will continue to be the opsec you practice with the private key file, in which case why spend the money on the Yubikey?)
    - filleokus 2y ago

thadt 2y ago

Good news then, since the article is discussing the discovery of that exact feature.