What Google 2-Step Verification (2SV) option should be used for cryptographic signature authentication?

The appropriate choice for cryptographic signature authentication in Google 2-Step Verification is Titan Security Keys. These keys use public key cryptography to provide a higher level of security compared to other verification options. They facilitate an open standard called FIDO (Fast Identity Online), which allows the device to generate a unique cryptographic signature for each login attempt. This means that when using Titan Security Keys, even if someone has your username and password, they would not be able to access your account without the physical key.

In contrast, other options, such as Google Authenticator and SMS Verification, rely on one-time codes that can be intercepted or phished, making them less secure. While Security Keys in general offer improved security over methods that depend solely on SMS or software-based tokens, Titan Security Keys, specifically, are built for strong, authenticated access through cryptographic means, reinforcing their suitability for scenarios requiring enhanced security measures such as cryptographic signature authentication.