I've been thinking about getting a couple of Yubikeys for a partner and myself, but we share certain accounts. While I would love to have the Yubikey 5 that can store TOTP, that seems like it could be problematic for shared accounts.
Would using the cheaper Yubico Security Keys to unlock Bitwarden Premium vaults, that use a Shared Organization, be a better/more sane option than trying to sync up TOTP secrets every time a new shared account gets added? Any other critiques or suggestions?
Can you use passkeys/webauthn/fido2/whatever instead of password+totp for the sites in question?
If so, like, do that: your yubikey supports that shit natively and will completely eliminate your migranes, other than having to make sure the passkey is on each device (which, honestly, is not that complicated.)
Some do have that option. Some do not. I plan to use the passkey option wherever possible, but even in 2024 going on 2025, there's still far too many websites and services that don't have passkey options.
The problem is that I need my partner to be able to access certain accounts in the event I'm unavailable, and those accounts don't always have the ability to register passkeys.
The attacker would need physical possession of the YubiKey, Security Key, or YubiHSM, knowledge of the accounts they want to target and specialized equipment to perform the necessary attack. Depending on the use case, the attacker may also require additional knowledge including username, PIN, account password, or authentication key.
So let's say I'm at work, I set up NewAccount to use Yubikey A. Partner has Yubikey B and isn't nearby. How would I share or retrieve that secret key later? My understanding is that's not possible if it's stored on the key, but maybe I'm wrong.
I’m not evaluating whether or not you should do that, but, assuming you trust your partner and their op sec, you could send them the secret via a disappearing message on Signal or some other E2E encrypted communication method.
You set it up on your key, they add it to theirs later, the secret disappears into the ether.
If you're just storing the password on the key then, no you can't get it unless you have the key. The main usage (arguably) for a yubikey is the FIDO2 auth method where you add those keys as MFA methods. That would allow access using either key.