5 ms·

Neat, but that also means their value as MFA is undermined. It's no longer "something you have" when it can freely be copied, including by a casual passerby or

by crote 4y ago

Neat, but that also means their value as MFA is undermined. It's no longer "something you have" when it can freely be copied, including by a casual passerby or a virus. You're basically reducing it to a password stored in a file called "MY PASSWORDS" on your desktop. Great for user friendliness, terrible for security. So now when you use Passkeys we'll need to add another 2FA instance to properly secure your account...

growse 4y ago
If MYPASSWORDS.txt is encrypted and can only be decrypted with a key stored in some sort of HSM, then it is still MFA.
- charcircuit 4y ago
  The point is if you can export the key from the HSM then it no longer requires that HSM as the exported key and MYPASSWORDS.txt can be bundled together. Knowing the contents of that bundle is a single factor of authentication.
  - growse 4y ago
    Yes, but this is tautological. "If I can clone a physical key, or create a copy, then it's not a good physical key" isn't particularly insightful.
- Dalewyn 4y ago
  So what you're saying is it's not encrypted, not secured, and should not be trusted? Seriously, how many key leaks and other compromises do we have to witness before we do away with the notion they're secure and trustworthy?
  - stavros 4y ago
    There is no notion that "something is secure". It literally doesn't exist. There is a notion that something is secure under a specific threat model, and there are many threat models for which keys are secure and passwords are not.
booi 4y ago
So you’re saying.. I should rename that file on my desktop?
nemoniac 4y ago
So an ssh private key is not "something you have" either then? It's certainly not something you know nor something you are. Where does it fit into the MFA scheme of things?
- deleted 4y ago
  [deleted]
- nsheridan 4y ago
  An SSH private key isn't "something you have" - it's not a physical object, you can make copies of it. To me it falls into "something you know". You might not be able to type it from memory into a file but in practical terms it's no different to a password, it just usually happens to reside on disk.
  - vasco 4y ago
    It is something you have, the machine where the file is. It's only something you know if the only way for me to steal it from you is to threaten you to say it. If I can just yank your open laptop from your lap in a cafe, it's something you have.
    - charcircuit 4y ago
      If you are able to copy it off the laptop it becomes something you know. One important property about something you have is that you the owner of the account have that thing in your possession then no one can hack you. If someone is able to copy it then that invariant is not true. Writing your password on a piece of paper doesn't turn that password into something you have.
      - vasco 4y ago
        It literally does. Now whoever _has_ that piece of paper can get to your account. A physical piece of paper with a password written on it is no different from a physical key. Unless you're going to say that if you memorise the indentations on your house key then your key is "something you know" too.
stavros 4y ago
I don't think it's mandatory, I think you'll be able to get a device that doesn't export, if that's what you want.
arghwhat 4y ago
Despite being an improvement, passkeys were never MFA. They substitute a single factor - your password - with one stored and managed in a safer way.
- jonathanstrange 4y ago
  My memory is definitely safer than my phone in terms of passphrase storage. So is a physical notebook.
  - rekoil 4y ago
    Yours may be, but that isn't true for the majority (dare I say >95%) of users. The problem is that people tend to simplify when forced to remember things, or re-use. A Passkey, even handled in the manner described in this post, is better for most people.
  - dpatterbee 4y ago
    That seems like hubris, the human is always the weakest link in the security chain.
  - asimpletune 4y ago
    Actually, I'm not even sure your memory is safer. You would have to remember hundreds if not thousands of passwords, including remembering which domain they belong to, as well as to be able to generate unique ones for every new domain you encounter for the rest of your life.
  - contravariant 4y ago
    Could luck performing a public key handshake from memory though.
- thedougd 4y ago
  If you were using webauthn as a second factor, I believe the passkey changes implemented by Apple and others means your device bound webauthn keys are now synchronized to their cloud services. That hurts and my enterprise had to halt their rollout of webauthn for MFA while we figure it out.
TacticalCoder 4y ago
> It's no longer "something you have" when it can freely be copied, including by a casual passerby or a virus Yup it's very sad. It's better, for regular people, compared to passwords but it's a complete step backwards compared to actual physical secrets stored behind an HSM (like inside an actual physical FIDO2 device). It is pure insanity that FIDO2/webauthn was, at last, getting somewhere and that we had something secure gaining traction and that the standard has been embraced and extended by the likes of Microsoft (and Apple and Google) to then greatly lower its security. While still pretending it's all still FIDO2/webauthn. And as I understand it it's really bad because companies using passkeys shall be able to force their users to use the less secure form of passkeys by actually refusing passkeys from those offering passkeys where the secret never leaves physical hardware. For a start it is pretty obvious that the less secure Google/Apple/Microsoft "password stored in a file on your desktop" (and backed in the (i)Cloud: what a concept for security keys!) you mention shall be accepted everywhere. While it's highly likely that at some point, "because convenience", they'll cut off passkeys vendors offering actually secure devices. And it's likely we'll have at the same time "security experts" explaining it's a godsend security-wise. > So now when you use Passkeys we'll need to add another 2FA instance to properly secure your account... As long as it's actually possible to do so. I fear that at some point it's going to be passkeys are the only auth option and by the way we accept "software passkeys backupable to the cloud" only. It's just sad. When you think that the original implementation of FIDO allowed users to detect if their security key had been cloned, thanks to the monotonic counter (I know for a fact because I verified this myself, with cloned security keys, both before and after Google removed that monotonic counter )... But since then Google (and others) removed that check (so it's already impossible to detect if your key has been cloned). This all makes me think there's more to it than "just" Apple/Microsoft/Google. I think it's highly likely some three-letter agency was involved in the "enhancement" of the standard.

by crote 4y ago

growse 4y ago

If MYPASSWORDS.txt is encrypted and can only be decrypted with a key stored in some sort of HSM, then it is still MFA.

charcircuit 4y ago
The point is if you can export the key from the HSM then it no longer requires that HSM as the exported key and MYPASSWORDS.txt can be bundled together. Knowing the contents of that bundle is a single factor of authentication.
- growse 4y ago
  Yes, but this is tautological. "If I can clone a physical key, or create a copy, then it's not a good physical key" isn't particularly insightful.
Dalewyn 4y ago
So what you're saying is it's not encrypted, not secured, and should not be trusted? Seriously, how many key leaks and other compromises do we have to witness before we do away with the notion they're secure and trustworthy?
- stavros 4y ago
  There is no notion that "something is secure". It literally doesn't exist. There is a notion that something is secure under a specific threat model, and there are many threat models for which keys are secure and passwords are not.

booi 4y ago

So you’re saying.. I should rename that file on my desktop?

nemoniac 4y ago

So an ssh private key is not "something you have" either then? It's certainly not something you know nor something you are. Where does it fit into the MFA scheme of things?

deleted 4y ago
[deleted]
nsheridan 4y ago
An SSH private key isn't "something you have" - it's not a physical object, you can make copies of it. To me it falls into "something you know". You might not be able to type it from memory into a file but in practical terms it's no different to a password, it just usually happens to reside on disk.
- vasco 4y ago
  It is something you have, the machine where the file is. It's only something you know if the only way for me to steal it from you is to threaten you to say it. If I can just yank your open laptop from your lap in a cafe, it's something you have.
  - charcircuit 4y ago
    If you are able to copy it off the laptop it becomes something you know. One important property about something you have is that you the owner of the account have that thing in your possession then no one can hack you. If someone is able to copy it then that invariant is not true. Writing your password on a piece of paper doesn't turn that password into something you have.
    - vasco 4y ago
      It literally does. Now whoever _has_ that piece of paper can get to your account. A physical piece of paper with a password written on it is no different from a physical key. Unless you're going to say that if you memorise the indentations on your house key then your key is "something you know" too.

stavros 4y ago

I don't think it's mandatory, I think you'll be able to get a device that doesn't export, if that's what you want.

arghwhat 4y ago

Despite being an improvement, passkeys were never MFA. They substitute a single factor - your password - with one stored and managed in a safer way.

jonathanstrange 4y ago
My memory is definitely safer than my phone in terms of passphrase storage. So is a physical notebook.
- rekoil 4y ago
  Yours may be, but that isn't true for the majority (dare I say >95%) of users. The problem is that people tend to simplify when forced to remember things, or re-use. A Passkey, even handled in the manner described in this post, is better for most people.
- dpatterbee 4y ago
  That seems like hubris, the human is always the weakest link in the security chain.
- asimpletune 4y ago
  Actually, I'm not even sure your memory is safer. You would have to remember hundreds if not thousands of passwords, including remembering which domain they belong to, as well as to be able to generate unique ones for every new domain you encounter for the rest of your life.
- contravariant 4y ago
  Could luck performing a public key handshake from memory though.
thedougd 4y ago
If you were using webauthn as a second factor, I believe the passkey changes implemented by Apple and others means your device bound webauthn keys are now synchronized to their cloud services. That hurts and my enterprise had to halt their rollout of webauthn for MFA while we figure it out.

TacticalCoder 4y ago

> It's no longer "something you have" when it can freely be copied, including by a casual passerby or a virus Yup it's very sad. It's better, for regular people, compared to passwords but it's a complete step backwards compared to actual physical secrets stored behind an HSM (like inside an actual physical FIDO2 device). It is pure insanity that FIDO2/webauthn was, at last, getting somewhere and that we had something secure gaining traction and that the standard has been embraced and extended by the likes of Microsoft (and Apple and Google) to then greatly lower its security. While still pretending it's all still FIDO2/webauthn. And as I understand it it's really bad because companies using passkeys shall be able to force their users to use the less secure form of passkeys by actually refusing passkeys from those offering passkeys where the secret never leaves physical hardware. For a start it is pretty obvious that the less secure Google/Apple/Microsoft "password stored in a file on your desktop" (and backed in the (i)Cloud: what a concept for security keys!) you mention shall be accepted everywhere. While it's highly likely that at some point, "because convenience", they'll cut off passkeys vendors offering actually secure devices. And it's likely we'll have at the same time "security experts" explaining it's a godsend security-wise. > So now when you use Passkeys we'll need to add another 2FA instance to properly secure your account... As long as it's actually possible to do so. I fear that at some point it's going to be passkeys are the only auth option and by the way we accept "software passkeys backupable to the cloud" only. It's just sad. When you think that the original implementation of FIDO allowed users to detect if their security key had been cloned, thanks to the monotonic counter (I know for a fact because I verified this myself, with cloned security keys, both before and after Google removed that monotonic counter )... But since then Google (and others) removed that check (so it's already impossible to detect if your key has been cloned). This all makes me think there's more to it than "just" Apple/Microsoft/Google. I think it's highly likely some three-letter agency was involved in the "enhancement" of the standard.