I'm a programmer and it took me about an hour to implement and test a basic Two-Factor authentication algorithm using Google Authenticator. That includes creati

I'm a programmer and it took me about an hour to implement and test a basic Two-Factor authentication algorithm using Google Authenticator. That includes creating the QR code, creating the secret string and calculate the current one time password. If you have a decent programmer for your web application then the one time cost involved is very minimal for the benefit that it provides.