password - something you know and then forget and cracker dictionaries also already know key (sw or hw) - something you have and then lose,or malware finds the

password - something you know and then forget and cracker dictionaries also already know key (sw or hw) - something you have and then lose,or malware finds the spare copy under the mat, or turns out to be flawed as reported by academic cryptographers or as designed by NSA OAuth and federated login - one password to rule them all and then make malware devs happy when they phish you browser "DNA", keystroke analysis, behavioral analysis, pictures of kittens - something you collect amd then malware "in the browser" clones and drops on botnet 2 factors - 2 somethings that keep IT admins and vendors employed and then users log in to Facebook and circumvent corporate systems using more user friendly services smartphone - something that you have and then gets malware or lost or stolen or hacked via bluetooth everything the end user could possibly do conveniently is simply projecting an illusion of security anything that is inconvenient will drive away users (there's a reason Amazon has 1-click) i suggest Facebook or G+ and adding a big lock png next to your FB login button....end users will feel very safe, i assure you if you get traction - then hire/partner with very skilled developers who know how to write (or better reuse) high quality, secure code; add a very skilled network and systems security minded ops person to your team for best results if no traction - well, then...ummm.... YMMV