Patent ID: 7143296

Claim:
A computer-implemented method for controlling a video recording device over a network that is performed without using interior components of the video recording device, the computer-implemented method comprising: using a computer on a user side of the network to perform steps including, inputting information to generate at least a portion of an electronic mail, encrypting predetermined information, a first adding step of adding information encrypted in said encrypting step to said electronic mail generated in said inputting step as certification information, a second adding step of adding to said electronic mail a control command to control a reservation function of the video recording device to reserve an operation time thereof, transmitting through the network said electronic mail with said certification information added in said first adding step and said control command added in said second adding step and receiving an electronic mail indication from the network that no reservation for the requested operation time has been made when there is an overlap of the requested operation time with any previously entered operation times; and using a computer on a video recording device side of the network to perform steps including, receiving said transmitted electronic mail from the network at a location of the video recording device, a first extracting step of extracting said certification information from said received electronic mail, a second extracting step of extracting said control command from said received electronic mail, decrypting said certification information extracted in said first extracting step using a public key, certifying whether a sender of said electronic mail is an authorized user by referencing said certification information decrypted in said decrypting step, determining if the control command extracted in the second extracting step is seeking an operation time duplicating one already reserved and transmitting an electronic mail on the network indicating that no reservation has been made because the control command extracted in the second extracting step is seeking a duplicate operation time of one already reserved, storing said control command extracted in said second extracting step if said sender of said electronic mail has been certified in said certifying step to be an authorized user, and if the determining step determines there is no duplicated operation time request, and controlling said reservation function of the video recording device to reserve an operation time thereof based on said control command stored in said storing step.