Patent ID: 8196173

Claim:
A video transmission system including a video content source that has a timer, a video content sink, and video relayer devices, at least one of the video relayer devices comprising: a processing unit; a memory to store a calculation result and second key information, the calculation result being produced by the video content sink based upon first key information, and the second key information being associated with a second key held by the video content sink; the processing unit being configured to include, a key information transfer section to transfer first key information to the video content sink upon receiving the first key information from the video content source, the first key information being associated with a first key held by the video content source; a timer pausing section to control the timer of the video content source to pause upon receiving the first key information from the video content source; the processing unit being operable to receive the second key information and the calculation result from the video content sink and store the second key information and the calculation result, respectively, in the memory; and the processing unit being further configured to include, a timer resuming section to control the timer of the video content source to resume when the second key information and the calculation result have been stored, respectively, in the memory, wherein upon receiving the first key information from the video content source, the timer pausing section is further operable to notify the video content source that the video content source and the video content sink are not connected and to control the timer of the video content source to pause by turning off a hot-plug signal, and wherein, when the second key information and the calculation result have been stored in the memory, respectively, the timer resuming section is further operable to notify the video content source that the video content source and the video content sink are connected and to control the timer of the video content source to resume by transmitting a hot-plug signal.