Two-Factor Authentication (2FA)

List of services supporting 2FA: Two Factor Auth.org

You can also use hardware tokens for this.

You could generate time-based numbers (TOTPs) which could then be used as second factor (2FA) to enter for logging into your Google account.

Seems that the 2FA website for Google accounts doesn't support adding a TOTP generator like Google Authenticator or a FOSS alternative for new accounts since April 2019, which makes you rely on proprietary Google services on your phone to secure your account.

This is a bad thing because you now have to use the Google-flavoured Android – or, more precisely, the Google Play Services – even if you installed the non-Google flavoured Replicant or LineageOS.

• Aegis
• Authy
• andOTP
• Google Authenticator

• RSA SecurID
  • has EasyToken as FOSS alternative