An HDCP receiver device that receives frames from an HDCP transmitter device. The receiver device has a frame counter that is updated for each frame that is received from the transmitter device and that includes encrypted content, while the receiver device is in a pre-authorization mode. During the pre-authorization mode, the receiver device does not decrypt any received frame bearing encrypted content. While the receiver device waits to transition from the pre-authorization mode to a post-authorization mode in which the receiver device can begin to decrypt any received frames that include encrypted content, the frame counter is updated for each frame received that includes encrypted content. In the post-authorization mode, the frame counter has a nonzero value if frames including encrypted content were received by the receiver device during the pre-authorization mode.

Provided is an image forming apparatus performing effective automated storage tiering. When the system control part of the CPU causes the image processing part to perform image processing of data read from the SSD having a processing speed higher than that of the HDD, the tiering control part measures a ratio of an idle time by the image processing relative to a usage ratio per unit time of the CPU, and determines a movement destination of the data.