Please add your suggestions for this list of widely-deployed MFA technologies to this list. We're primarily looking for classes of technologies (e.g., smart phone app or key fob), but feel free to specify vendors or products, if you think they warrant individual mention.
- Second factor only
Duo (used in conjunction with username/password)- Duopossibly with restrictions)
- OTP tokens
- U2F
- Multi-factor tokens
- PKI with PIN or passphrase