These sophisticated biometric security devices work by measuring things that are unique to you, like your fingerprint, your voice, your face, and even your retina.
Last week, Apple announced its new iPhone 5S would use fingerprint scanning to unlock the phone and even to make purchases. But amid the excitement, came serious questions about privacy.
Apple quickly assured customers that the iPhone's new touch ID sensor doesn't store an image of your fingerprint on the phone, only a numerical code that remains encrypted within the processor.
More and more, this technology is becoming a part of everyday life. Biometrics is being used to identify employees at the office, to buy lunch at school, or even check in at the gym.
"Consumers are overwhelmed today by passwords and pins and cards that they have to use to access all the things that are available to us now and they're no longer secure but, more importantly, they're becoming very inconvenient," said Michael DePasquale with BIO-key International.
But do these bio signatures increase the risk of a security breach? BIO-key International says one of the biggest myths is that a person's fingerprint could be made public. That's not true. First, their software enlarges your print by more than 40 times, and then it captures about 2,000 points of "data." After that, patented technology connects those dots to create a map. That's what's stored, not your print.
Plus, there are other precautions. For example, one blood bank where fingerprints are used to identify donors uses triple encryption to keep everything private.
"It's virtually impossible for anybody to steal your identity without your biometric finger data," said Jayne Giroux with Suncoast Communities Blood Bank.
What about other privacy issues?
"I don't think it's concerning or alarming so long as there are protections in place and consumers are notified about how this information is going to being used and they're assured that the data is stored securely," David Jacobs, EPIC consumer protection counsel.
Still, privacy advocates say they're keeping a close watch on how this technology evolves, because nothing is hacker proof.
"In the near future, biometric information could be as useful for identify theft as a Social Security number. It could even be more problematic because if your credit card number is compromised, the bank can just issue you a new credit card, but it can't issue you a new iris," said Jacobs.
Another thing to keep in mind is that many devices, such as the new iPhone 5S, will allow you to opt out of the fingerprint technology. And the same is true for most gyms. Security experts suggest asking what personal information is being stored and, more importantly, what is being shared.