Manish_Singh - 7:01 pm on Sep 8, 2010 (gmt 0)

Very similar system is used by my local bank. The only difference is

- they send access code to both Email and SMS.
- the access code is valid for a certain period of time (meaning, if I log out and log in again, I can use the old access code for next few hours).

At times the SMS gets delayed or my phone is out of signal range. In those times email comes in handy.

A problem that I have faced with this solution is that sometimes both SMS and Email get delayed (even a 1 minute delay in annoying when you simply want to login), so I end up generating multiple access codes. All of those different access codes arrive at the same time and then you are confused as to which one is the latest one.

I do not know the exact costs but you may also want to check the verisign identity protection system.