Making sure your machine knows it is you

Technologists say just one trick is unlikely to unlock the problem of authentication. One set of tools may verify identity on Web sites; another may unlock cars; still another could grant access to bank accounts.A coalition of hardware and software companies, calling itself the Fido Alliance, is working on a set of specifications for password alternatives that the industry can rally around. Its guidelines are expected to be released at the end of the year. Companies affiliated with Fido are already testing products, like fingerprint readers and software that recognizes faces and voices.

One day, users might be able to log into a favorite e-commerce site by speaking into a computer and buy something with a gaze at a mobile PayPal app.Facebook has perhaps had the most success in becoming a one-stop identity verification service. Millions of Web sites allow users to log in with their Facebook credentials, which is also a way for Facebook to get to know you better - and serve you more tailored ads. The dangers are obvious. A thief with your Facebook credentials can pretend to be you across the Web.

Mozilla has been trying to popularize its Persona alternative to that single sign-on system. Mozilla makes sure your e-mail provider verifies that the account belongs to you. Then, for every site that accepts a Persona login, you can log in with the original verified e-mail.A more fantastical solution is being developed in a lab at the University of California, Berkeley. Computer scientists there say a simple and cheap headset will be able to read your brain waves to verify your thoughts - and save you the work of typing in a password.