#twofactorauthentication
Science & Technology | Security
Is the Cost of 2FA Too High? Two-factor Authentication Methods -
Two-factor Authentication Methods: there's no need to spend hundreds of thousands of dollars to protect your environment with 2FA, like RSA’s SecurID.
Science & Technology | Security
Two Factor Auth List
List of sites with Two Factor Auth support which includes SMS, email, phone calls, hardware, and software.