361–370 of 525 posts
It would be nice for Amazon to commit as well. AWS has support for only a single Yubikey, which is mostly useless, unless you don't care about being locked out of your account if you lose that one key.
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I think the whole point of HSMs is that you can’t back up (read: exfiltrate) the master secrets. Having said that, on certain Yubikeys you can store PGP keys on them, and put the same secret key on several different Yubis. If you’re relying on a hardware key it’s probably a good idea to have a backup key and make sure both are registered with whatever system you’re accessing. LastPass and GitHub at least support addi…
> I think the whole point of HSMs is that you can’t back up (read: exfiltrate) the master secrets. You're getting it backwards though. You are right that the whole point of an HSM is to not leak secrets when connected to a compromised computer. However there's nothing wrong with a HSM device that can be initialized with a "seed" of your liking, as long as that initialization step is done in a fully offline / airgappe…
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It's literally the opposite. You "must" have a cryptographic device (a dongle) that is only doing that one thing, authentication. Doesn't have a built in radio (unless for NFC, if you want it), doesn't have any microphone or camera, doesn't store any data beyond what's needed to authenticate, doesn't communicate except to authenticate - bi-directionally, so phishing is no longer a thing, or at least it's a lot harder…
> It's very hard to make a privacy case against FIDO. With username and password, I have full control over my privacy in a very easy to understand fashion: If I randomly generate them I know I cannot be tracked (as long as I ensure my browser doesn't allow it by other means). With those keys I have a opaque piece of hardware which transfers an opaque set of data to each website I use and I have NO idea what data that…
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I think the whole point of HSMs is that you can’t back up (read: exfiltrate) the master secrets. Having said that, on certain Yubikeys you can store PGP keys on them, and put the same secret key on several different Yubis. If you’re relying on a hardware key it’s probably a good idea to have a backup key and make sure both are registered with whatever system you’re accessing. LastPass and GitHub at least support addi…
You'll need to generate the key on a less secure host to do that, though, which partially defeats the purpose of a hardware key in the first place. As far as I understand, "real" HSMs (i.e. the expensive, rack sized type of security key) sometimes offer the ability to export their root key to other models by the same manufacturer using a specific ceremony. Arguably this also significantly weakens the security of the…
This only needs to be done once. For example by booting an old computer with no wifi capabilities and no hard disk from a Linux Live CD.
> You'll need to generate the key on a less secure host to do that, though, which partially defeats the purpose of a hardware key in the first place.
I kinda disagree with that. I generated my key by throwing physical dice. No random number generator to trust here. I only needed an offline/airgapped computer to compute the checksum and that program cannot lie: I know the first 256 bits out of the 264 bits so the program computing the checksum cannot lie to me, it's only giving me 8 bits of checksum.
Then I only need to trust the specs, not the HSM vendor.
Now, sure, my old Pentium III without any hard disk and without any WiFi, without any physical ethernet port, may be somehow compromised and exfiltrate data through its fans or PSU or something but what are the odds here? Especially: what are the odds compared to the odds of having a rogue HSM vendor selling you U2F keys for which it fully knows the secret?
I'd argue this requires less trust than the trust required in buying a pre-initialized HSM device.
Are there any FIDO security keys that explicitly support backing up and restoring their master secrets? I would love to move from Username + Password + TOTP but my current workflow requires that I am able to regain access to my digital accounts using nothing but a few page paper backup including core service passwords & exported TOTP secrets.
Yup there are for sure, for I tried it and it works. Now: I tried it out of curiosity and I'm not actually using it atm, so I don't where it's at but...
I tried on Ledger hardware wallets (stuff meant for cryptocurrencies, but I tried them precisely for the U2F app): initialize the device with a seed of my own and then register to FIDO2/U2F/webauthn sites. Worked fine.
Took a second hardware wallet, initialized it with the exact same seed: boom, it's working fine and I could login using that 2nd HSM device as the 2FA.
Note that as soon as I used the 2nd device, the first one wasn't working anymore: if I wanted it to work again, I'd need to reinstall the U2F app on the HSM device (the way the device work is it only accepts apps that are signed, and that is enforced by the HSM itself: the HSM has the public key of the Ledger company so it can only install "apps", like the U2F app, that is actually signed by Ledger... I'm not saying that's 100% foolproof, but it's not exactly the most hackable thing on earth either).
The reason you cannot use both devices at once is because of how an increment number is used: it has to be monotonicaly increasing and when the app is installed on the HSM, it uses the current time to initialize its counter.
I haven't checked these lately: I know the specs evolved and I know Ledger said they were coming with a new U2F app but I didn't follow the latest developments.
Still: I 100% confirm you that it's not only doable but it's actually been done.
Are there any FIDO security keys that explicitly support backing up and restoring their master secrets? I would love to move from Username + Password + TOTP but my current workflow requires that I am able to regain access to my digital accounts using nothing but a few page paper backup including core service passwords & exported TOTP secrets.
> Are there any FIDO security keys that explicitly support backing up and restoring their master secrets? Yup there are for sure, for I tried it and it works. Now: I tried it out of curiosity and I'm not actually using it atm, so I don't where it's at but... I tried on Ledger hardware wallets (stuff meant for cryptocurrencies, but I tried them precisely for the U2F app): initialize the device with a seed of my own an…
EDIT: you basically save a 256 master seed as a list of 24 words (out of a fixed dictionary of precisely 2048 words, so 11 bits of entropy per number). 264 bits altogether: last word contains 3 bits par of the seed and 8 bits of checksum.
Trivial to write down. Very little chance of miswriting it for: a) you must prove to the HSM you wrote your seed down correctly and b) the dictionary is known and hardly any word can be mistaken for another.
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Software ("virtual") implementations are already possible in WebAuthn. It's up to the service whether to allow enrollment via a software authenticator; most services will want to allow this, seeing as it's still way more secure than ordinary username/password.
A much more secure way of doing this is to use the platform's/OSs most secure way of storing private keys, which in many cases is hardware (Secure Enclave on iOS, TrustZone or "real" secure hardware like Titan M on Android, TPM on Windows/Linux). This is already supported by many browsers (unfortunately Mozilla/Firefox are dragging their feet on this one [1]) and gives you exactly the user experience you want. [1] ht…
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I think the whole point of HSMs is that you can’t back up (read: exfiltrate) the master secrets. Having said that, on certain Yubikeys you can store PGP keys on them, and put the same secret key on several different Yubis. If you’re relying on a hardware key it’s probably a good idea to have a backup key and make sure both are registered with whatever system you’re accessing. LastPass and GitHub at least support addi…
The ability to have a backup does not imply any ability to exfiltrate the master secrets. It is enough to have a means to wipe out any information contained in the device, including any master secret. At that point, there should be a means to enter a new master secret in the blank device, before proceeding to use it normally. If a device provides this feature and it does not contain any other secret information intro…
Precisely. The Ledger Nano S (and probably the Nano X too) allows to do exactly what you describe, the very way you describe it (three wrong PINs, on purpose or not, and the device resets itself to factory default and, as you wrote, at that point it's unusable until you enter again a master secret (either your old one or a new one: the device has no way to know and doesn't care).
Are there any FIDO security keys that explicitly support backing up and restoring their master secrets? I would love to move from Username + Password + TOTP but my current workflow requires that I am able to regain access to my digital accounts using nothing but a few page paper backup including core service passwords & exported TOTP secrets.
I think the whole point of HSMs is that you can’t back up (read: exfiltrate) the master secrets. Having said that, on certain Yubikeys you can store PGP keys on them, and put the same secret key on several different Yubis. If you’re relying on a hardware key it’s probably a good idea to have a backup key and make sure both are registered with whatever system you’re accessing. LastPass and GitHub at least support addi…
Earlier quoted context omitted.
My vision of future authentication (shared by colleagues in security) is based in strong hardware credentials and additional layer-7 context about identity, device and location. Basically, more identification of you and your browser using cryptographically-guaranteed and immutable events. It is actually the deprecation of passwords altogether and generally moving the trust boundary away from the control of the user e…
I don't know if you're being sarcastic, but your vision sounds like a nightmare and not very far removed from Gattaca. > moving the trust boundary away from the control of the user entirely. I also don't enjoy it, but it would solve a lot of current problems we see in information security. Every despot throughout history has noted that freedom can be traded for security, but I thought that most of us would agree that…