Time-limited key derivation

Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for time-limited key derivation. In some implementations, a module receives a request that provides a key identifier and obtain a control value indicating a future time. The module obtains a counter value indicating a first time, where the counter value is based on a current state of a counter, and where the counter is configured to update the state of the counter at a predetermined frequency. The module generates a comparison result based on comparing the control value indicating the future time with the counter value indicating the first time. The module generates a key based on the key identifier, the control value, the comparison result, and a stored random number, and the module provides the key in response to the request.