Methods, apparatus, and computer-readable media are described herein related to biometric authentication. A first computing device can detect a machine-readable code displayed by a second computing device, where the machine-readable code can identify protected information viewable via the second computing device. In response to detecting the machine-readable code, the first computing device can acquire biometric data via one or more biometric sensors associated with the first computing device. Based at least in part on the biometric data, the first computing device can generate an authentication message that includes authentication information and identifies the protected information. The first computing device can then send the authentication message to an authentication server for verification of the authentication information, where verification of the authentication information can allow access to the protected information via the second computing device.