This disclosure describes techniques that facilitate granting an access privilege to a client device based on selectively authenticating biometric data. Particularly, a biometric authentication system may generate an authentication policy that authenticates a client identity via biometric authentication protocols. The authentication policy may be based on a security policy of the computing resource associated with the access privilege. The biometric authentication protocols may be based on a kinematic behavior, body chemistry, or physical features of the client. Each biometric authentication protocol may be assigned an authentication score that reflects a confidence that a biometric sample used to gain an access privilege does in fact correspond to the client. Further, an authentication policy may include a random selection of biometric authentication protocols that comply with a security policy of the computing resource. An authentication policy may be further based on a client disposition, environmental conditions of the client device, or both.