> they have enough storage on board to hold more than 250 unique passkeys.
Resident key を250個より多く設定できるのかな？OpenPGP も使えるなら良い選択肢かもしれない。
Google’s new Titan security keys are ready for a world without passwords - The Verge https://www.theverge.com/2023/11/15/23962443/google-titan-security-key-passwordless-login
The Verge · Google’s new Titan security keys are ready for a world without passwords
OpenPGP についての記述は見あたらない。使えないのかもね。
Titan Security Key - FIDO2 USB-A/USB-C + NFC https://store.google.com/product/titan_security_key
ちょ、GoogleのブログではTitanが覚えられるパスキー（resident keyのことだろう）は250個まで（up to 250）じゃんかー。どこでまちがいた…
A new Titan Security Key is available in the Google Store https://blog.google/technology/safety-security/titan-security-key-google-store/
Google · The latest Titan Security Key is in the Google Store