GENERATING CRYPTOGRAPHIC KEYS USING SUPPLEMENTAL AUTHENTICATION DATA

Techniques are disclosed relating to generating cryptographic keys using supplemental authentication data for use in user authentication. In one embodiment, an authentication application executing on a computing device may access an initial cryptographic key that is shared with an authentication server configured to authenticate a user of the computing device to a service provided by a server system. The authentication application may execute a routine to obtain a supplemental authentication data value that is not stored by the computing device prior to executing the routine. Further, the authentication application may generate an updated cryptographic key based on the initial cryptographic key and the supplemental authentication data value. In some embodiments, the authentication application may use the updated cryptographic key to generate a one-time passcode that, when communicated to an authentication server, is usable to authenticate the user to the service.