4 ms·
It’s a little odd to me that the author hopes FIDO keys as a single factor is rare. This is explicitly supported by FIDO and Yubico, and available in the Micros
by md_ 5y ago
It’s a little odd to me that the author hopes FIDO keys as a single factor is rare. This is explicitly supported by FIDO and Yubico, and available in the Microsoft ecosystem (https://support.microsoft.com/en-us/windows/sign-in-to-your-microsoft-account-with-windows-hello-or-a-security-key-800a8c01-6b61-49f5-0660-c2159bea4d84 https://support.microsoft.com/en-us/windows/sign-in-to-your-...)!
As tomxor said elsewhere here, though, batch attestation allows you or relying parties to check that the key is a “real” Yubico key.
- sascha_sl 5y agoIt's available, but in practice it is almost never used without very robust backup factors because the support overhead from people losing their keys would be immeasurable. Much easier to bind people to phone numbers, despite them being really bad identifiers.
- edent 5y ago(Author here) I hoped it was rare because it seems like an obviously bad idea. I can see how it would be convenient - but that's often the opposite of secure. I wonder where it would make sense though?
- b3morales 5y agoHow would this differ from using an SSH key? Don't we do this all the time? Given prior authorization to add the factor, it is afterwards used on its own to authenticate.
- tialaramex 5y agoAlmost anywhere? It's much more convenient than the "type in your username" step. To be clear: Things you can do with FIDO2 include: * Just a "second factor". The authenticator has no memory of who it is, RPs (Relying Parties, e.g. web sites) basically provide prompts, which they derive from looking up a username you entered. The RP says if this is tialaramex, you'll recognise this arbitrary ID you gave me when enrolling and sign this freshness proof. The authenticator checks if it recognises the ID and if so retrieves the private key and signs the message, voila. * "Passwordless". The authenticator is behaving the same, but now the RP is only taking a username first, there may be no second factor. This is more secure than most passwords today, but is only a single factor. * "Usernameless". The authenticator now needs to remember every RP it has enrolled with, because the RP won't prompt it. Given the name of an RP (e.g. "news.ycombinator.com" the authenticator needs to replay the ID it gave when enrolling, and sign a freshness proof "I'm still, uh, tialaramex apparently". In a corporate environment, or perhaps banking, you can insist (via a thing called "Attestation") that the authenticator provides proof it is a real authenticator made by, e.g. Yubico and based on that claim trust it to do multi-factor authentication itself. Yubico's cheaper products do PIN auth, so you touch the sensor and type in say, "MyFuckingSecret" as PIN, the PIN is not sent to the Relying Party, they just get a message saying "Here's proof I'm that Yubico Yubikey which enrolled, and I say this is still the same human who enrolled me, I checked using a method my vendor says is suitable". Yubico's most expensive product, and the Google Pixel series, and some iPhones, use a fingerprint as their additional factor. Again though, the authenticator just says "I promise I checked, this is who made me, trust or don't" it doesn't send fingerprints anywhere.
- smileybarry 5y agoPasswordless login doesn't necessarily mean a physical separate dumb key, it can have many implementations that make sense: 1. WebAuthn (current spec) is also implemented by Android, iOS macOS and Windows 10/11 (natively); that makes your device a possible "passwordless factor holder". You then essentially tie your authentication with your device passcode and/or biometric ID, similar to what a password manager would do, except there's no password to steal. 2. YubiKey BIO supports biometric authentication (I presume with on-board fingerprint verification) to use the device's keys. So it's essentially a biometric-protected private key. 3. IIRC some hardware crypto wallets can act as WebAuthn devices and display the website domain when asking you to touch it. Maybe they support passcode protection? 4. Even if you were to use a "raw" WebAuthn key stored on your computer (on TPM, Secure Enclave, or even filesystem) -- if you protect it with a password, you essentially have pubkey authentication with a second factor of password.
- yjftsjthsd-h 5y agoWhy is it an obviously bad idea? It reduces login to a single factor of a physical object you possess, but for many people that's probably good enough. I mean, most people's physical houses are only protected by a physical key with single factor authentication and nobody seems to mind that.
- judge2020 5y agoI guess for physical keys, it means you losing it instantly triggers anyone with it access to your M$ account, so eg. TSA could take it from checked luggage, plug it in, and go snooping through your email. Webauthn on Windows via regular TPM is good in that it's not really tied to the computer's cryptographic key, it requires some wrapped data stored by Windows as well (when I reinstalled Windows 11->Windows 11 from scratch none of my Webauthn logins worked, it was like I had a new key entirely).
- postalrat 5y agoThe physical keys I have require a PIN to be entered before they function. I haven't looked into the specifics but it's possible the token denies attempts after a certain number and possibly deletes itself after a certain number of attempts fail in a row.