The idea is a good one: Use the cellphone camera to take a selfie and employ it as another login authentication credential.

Say Cheese

Both MasterCard and LogMeOnce have introduced a type of selfie authentication. The MasterCard process is very straightforward: If someone is buying a product from a participating merchant, the customer will get a push notification to the mobile device, which opens the selfie authentication app.

Users are then asked to blink (to show that they are living people and not just holding up a photo) and snap a picture. The app compares the photos taken to the one submitted by customers at the time of registration to verify their identity. The purchase is then approved and completed.

MasterCard announced its app last fall. Another vendor, LogMeOnce, recently added selfie authentication to its multifactor authentication service. LogMeOnce claims several hundred apps are already supported with the process. They rely on the end user verifying the photo on their mobile device — you can swipe right and left to see GPS and IP address details for further confirmation of your identity — and then use the photo as a master password to unlock your password vault.

Eliminating Authentication Weaknesses

Why are these tools important? There are weaknesses in all kinds of one-time passwords, including any selfie authentication. These weaknesses have been known and exploited for years: An attacker swaps the ever-changing part of the authentication process (the photo or the changing series of digits generated by a one-time password server) with something that appears to be dynamic but isn’t.

Security analyst Bruce Schneier addressed one such attack back in 2009. “We have to stop trying to authenticate the person; instead, we need to authenticate the transaction,” he wrote. “The current wave of attacks against financial systems are not exploiting vulnerabilities in the authentication system, so two-factor authentication doesn’t help.”

Indeed, there are still issues today. Wired published a scare story about not using SMS texts as the additional factor because of potential man-in-the-middle (MitM) attacks. The additional authentication factor “isn’t an invincibility spell. Especially if that second factor is delivered via text message,” Wired stated. “For services like Twitter that only offer second factor protections that depend on SMS, it’s time to wake up, smell the targeted attacks and give users better options.”

Wired cited the case of one well-known community organizer who had his Twitter account taken over. The attacker intercepted the one-time authentication codes by impersonating the victim and convincing the carrier to forward the text messages.

Is Selfie Authentication the Future?

Clearly, we need better authentication tools to manage the many passwords we amass as we use more and more online services. A number of vendors are working on other mechanisms besides selfies, such as PasswordlessApps’ Tidas project. This service uses the private encryption keys inside the more recent iPhones to sign and encrypt your data.

Its software development kit requires only a fingerprint and the TouchID button on the phone to login — no password required whatsoever. This is a great idea, since all private information is stored inside the iPhone and nothing is transmitted anywhere else.

This is only the first step in the path toward better authentication measures.