I just purchased a Yubikey 5 NFC. I want to use it to make my accounts a little more secure. I have added 2fa to my facebook account and I have added that key to my yubikey. So far, so good.

Now I have downloaded the Yubico Authenticator. I understand I need this to read a key through NFC off my yubikey.

But when I try to add a new account to my authenticator I get asked stuff like SHA algorithm (1, 256 or 512). Is it counter based or time based? Etc. How do I know which of these settings facebook uses for their keys?

Or have I totally misunderstood the concept?

  • 1
    You should be able to use U2F on Facebook with your YubiKey, no Yubico Authenticator app required – Joe May 23 at 20:01

See my last edit bellow

As far as I know there is no way to convience browsers to use devices such as Yubi because they are not using OS Crypto API at all. It is still under design. Also, as far as i know, Facebook (i am not using it at all) have no application installable on the computer (of any type, except mobile phones) which would use the certificate store. I am not sure if Android supports NFC keys to authenticate something but I would be very afraid of that.


According to this https://www.yubico.com/works-with-yubikey/catalog/facebook/ and this https://www.facebook.com/help/401566786855239

it should be possible with "latest versions of Opera or Chrome"... I have no clue how it works, but I also found this:


As I have no Yubi with me now I can't test it.

Ok, got it. It is not cryptoapi at all. It is U2F and it should be available in all browsers. So yes, it must be possible even without any additionall app

According to what I have read just add a key in Facebook the plug the Yubi and push the button.

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