Answer:
Something you are includes fingerprints, retina scans, or voice recognition. Something you have includes smart cards, token devices, or keys. Something you know includes a password, codes, PINs, combinations, or secret phrases. Somewhere you are including a physical location s or logical addresses, such as domain name, an IP address, or a MAC address. Something you do includes your typing rhythm, a secret handshake, or a private knock http://en.wikipedia.org/wiki/ Password_authentication_protocol#Working_cycle http://en.wikipedia.org/wiki/Smart_card#Security