A video source device provides a basis value to a symmetric ciphering/deciphering process to a video sink device, to which the video source device is to provide a video content. The video source device ciphers the video content for transmission to the video sink device, including generation of a first cipher key through functional transformation of the basis value. The video source device further verifies periodically that the transmitted video content is indeed being symmetrically deciphered by the video sink device. The video sink device practices symmetric deciphering, including generation of a first decipher key through functional transformation of the basis value. The video sink device also provides verification values to the video source device to facilitate confirmation of symmetric deciphering. In one embodiment, the video source and sink devices further authenticate each other, including generation of an authentication key, which is used in the generation of the first cipher/decipher key.