'Use for vault encryption' Error -- Linux/Firefox

[coldreactive]

I have this issue: Login with Passkey, "Use for vault encryption"

I’m using Arch Linux and Firefox. The YubiKey works with Google in firefox. I get the error

Error reading passkey. Try again or uncheck this option.

When trying to add it as a login option and for vault decryption. But I can add the passkey via passkeys otherwise without issues. it just won’t let me turn on login/vault decryption with it.

[coldreactive]

This still happens even after installing required packages I forgot to install, and rebooting the system:

sudo pacman -S yubikey-manager libfido2

So it’s not a user-error.

[Nail1684]

@coldreactive Welcome to the forum!

What Arch Linux version – and Firefox version – are you using?

Did you try it with a Chromium-based browser?

[coldreactive]

I don’t like the web rendering engine chromium/etc. uses (webkit/blink/whatever.) Because it causes problems with refreshing pages properly (aggressively tries to use cache), forcing me to CTRL+SHIFT+R all the time. Also, I’d prefer to keep ublock origin. I’m using EndeavourOS with the latest arch updates, and thus the latest Firefox, 147.0.2 (64-bit).

Linux 6.18.7-arch1-1
KDE/Plasma 6.5.5

[Nail1684]

Okay, but I wasn’t trying to convince you to change your browser permanently – I was just suggesting to test if the passkey creation would work with another browser…

[coldreactive]

That works. I’m unsure why. Probably because firefox didn’t ask to create a pin. Which chromium did. Now I can uninstall chromium, because logging in via the yubikey works fine in firefox. (Firefox even brings up a pop-in that asks for the pin I created on chromium.) I don’t know why firefox cannot ask to create a pin, even though it can ask for the pin created on another browser.

The only downside, is that the extension still requires the master password, and cannot ask for the security key, which is also what I wanted.

[Nail1684]

@coldreactive

The only downside, is that the extension still requires the master password, and cannot ask for the security key, which is also what I wanted.

Firefox, unfortunately, lags behind regarding passkeys – see e.g. here:

Firefox and passkeys

I’m a little sad myself to report this – as I still like Firefox – but Firefox still (or even more now?) lags behind in regards to passkeys and expanded passkey capabilities: [2025-09-26--11-41-23-vivaldi_WR51EEZSOD]   [2025-09-26--11-41-30-vivaldi_jpY4YQAqwa]   → Source: passkeys.dev - Device Support (screenshots from today)

… and for “Log in with passkey” itself… – also see e.g. here:

Sign into Bitwarden with a passkey / "Login with passkeys" (for all BW apps)

Unfortunately only Chromium and derivative browsers can support this currently. Tracking issue for Firefox: W3C WebExtensions discussion: From a quick search for “relying party” on the WebKit issue tracker, it doesn’t seem anyone has opened an issue there yet.

(so, at least for now, “Log in with passkey” and “Unlock with passkey” will only be available for the Chromium-based browser extensions)