Supply authentication via timing challenge response

摘要

In an example implementation, a print supply cartridge comprises a microcontroller to receive a timing challenge and enable authentication of the cartridge by providing a challenge response. The challenge response is provided in a challenge response time that falls within an expected time window.

主权项

1. A microcontroller to authenticate a replaceable supply device, the microcontroller comprising:
an interface to provide communication with a host device including to receive a timing challenge from the host device and to provide a challenge response to the host device within an expected time window following issuance of the timing challenge; and dedicated hardware logic to perform a mathematical calculation in response to the timing challenge, wherein a number of iterations of the calculation yields the challenge response within the expected time window; wherein the tuning challenge from the host device includes challenge parameters comprising a session key, a random seed, and a calculation count that specifies a number of times to perform the mathematical calculation.