4a: Passkey info: https://learn.microsoft.com/en-us/windows/security/identity-protection/passkeys/?tabs=windows%2Cintune
4b: KeePassXC 2.7.7: https://keepassxc.org/blog/2024-03-10-2.7.7-released/
4c: Websites that support passkeys: https://www.passkeys.io/who-supports-passkeys
4d: Microsoft makes passkeys the default authentication method for all new accounts: https://www.tomshardware.com/tech-industry/cyber-security/microsoft-makes-passkeys-the-default-authentication-method-for-all-new-accounts
4e: Microsoft’s new “passwordless by default” is great but comes at a cost (Seth): https://arstechnica.com/security/2025/05/microsoft-pushes-unphishable-logins-forward-with-new-sign-in-options/