An electronic signal transmission apparatus executes an authentication process with a transmitting electronic device over a transmission line and receives an encrypted signal and first and second key information therefrom. The encrypted signal is decrypted based on the first key information, displayed and/or recorded, and re-encrypted using the second key information. The encrypted signal is transmitted to another electronic transmission apparatus if that apparatus does not have a recording capability and determined to be authorized using a second authentication process. The re-encrypted signal is sent to the another electronic transmission apparatus if that device has a recording capability and is authorized.