If the barrage of data breaches and hacks over the past few years has taught us anything, it’s that passwords alone provide a pretty weak security system.

The problem is that a string of letters and characters alone will always be relatively easy to hack or steal, especially through trickery like phishing attacks over email. And to make matters worse, many people use the same password for more than one account, making it easier to get hold of all kinds of valuable personal information.

But the good news is the tides are slowly changing, and companies are increasingly experimenting with emerging technologies that could replace passwords.

Here’s a look at the four password alternatives that companies are working on now.