DEVICE AND METHOD FOR PREVENTING ILLEGAL COPY OR UNAUTHORIZED WATCHING OF DIGITAL IMAGE

摘要

PURPOSE: A device and method for preventing illegal copy or unauthorized watching of digital image are provided to automatically carry out authorization and key exchange in the case of power-on or connection between digital VCRs. CONSTITUTION: A device for preventing illegal copy or unauthorized watching of digital image includes a demodulating and error correcting part(1) for demodulating analog broadcasting signals and carrying out RS decoding, an ATV decoder(2) for descrambling an output from the demodulating and error correcting part according to descrambling information, a copy-preventing processing part(4) for separating a scrambled recording signal to a bit stream and an encoded key stream, and a smart card(3) for decoding the encoded key stream and an index code of the ATV decoder for outputting the descrambling information to the ATV decoder.