WebAuthN Not Working on Restore

Two Factor Authentication
1

Hi All,

I have two OnlyKeys. I have one OnlyKey I use as a primary which I backup and restore to a second OnlyKey that I keep for recovery purposes in the event that the first OnlyKey is ever lost of fails.

I only ever use the primary OnlyKey when registering for any service including WebAuthN.

Last week I backed up my primary OnlyKey using the app and restored the backup to my secondary key. For good measure I tend to use my secondary key for a couple of days to ensure the key is working as expected.

When logging into any webiste using WebAuthn I now get the error “Authentication via WebAuthn device failed.”, “Error while validating your second factor” etc. when using my primary key but the secondary key which I restored the backup to works as expected.

What would cause this?

Thanks,

Adam

2

Unfortunatly for you Fido2 tokens have a use count.
Each time you connect to a site this use count increment and is given to the website witch store this
count.
If you connect to the same site with a copy of your FIDO2 token which have a lower count the website detect something wrong append and reject your token.
This is implemented in the FIDO protocol especially to detect and reject duplicated tokens.

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3

Yes this is correct, FIDO2 utilizes a counter. This is why only one of your keys will work, when you used the secondary key for a couple of days that became your primary key and the one FIDO2 works with. If you were to backup and restore again to the other key you could use that one as primary.

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