requirement not clear. if true identity kind of hard because you have to manually verify each with some external parties like thomson reuters world check (which does not include every single person) or NRD (which do not have external API), or you talking about something else like 2 step auth which previous poster already answer.

Make you requirement clearer and post at right board next time. this board is for Internat related software, which are already published and being used, not to ask question about your not-related-to-internet-software which you not even start writing yet.

failed.

HTML alone can't. you need server side thingy to do it. store some data in db and script to process it.