6 Things That Could Replace Your Password

3. YOUR EYES
You’ve seen iris scans in 100 movies: You stare at a computer and it obtains images of the irises and detects patterns. If you’re you, you’re granted access. If you’re not — and are not equipped with eyeballs you’ve removed from a hapless guard or scientist, dudes with guns swarm in.

The devices are more costly than the ones that detect fingerprints and heartbeats, which makes them unappealing to tech companies. Currently, they’re used at border crossings and in national ID systems. While the eye is tougher to copy than fingerprints, some machines can be fooled using high-res digital images. Also, somewhat bizarrely, consuming alcohol can throw them off. (Wait, so the machines drink?!)