The only true open hardware and open source key is the Nitrokey Start, running Gnuk firmware. Other nitrokeys are open hardware but run a smartcard (hsm or pgpcard) and those firmwares are not fully open. Yubikey is closed source and this posts bugger is closed as well. Go for a Nitrokey if you value true openness.
I am not sure I follow? I have been using NitroKey Starts with ed25519 and GnuPG for two years without problems?
The NitroKey Start is great! I have switched to YubiKeys, since they are more durable and also support U2F/Fido2 and PIV on the same token. But NitroKey's software being open source and upgradable are great features.
Note that gnuk also works on Blue Pills. So, if a NitroKey is too expensive for you, you can pick up a couple of Blue Pills for a few dollars and flash gnuk on them. [1]
Kidding aside: I'm sure there are many more prodcuts having problems like this. Just goes to show there's no such thing as 100% secure I guess. At least this is open so can be fixed with some effort.
