Research On Disc Play With Data Encryption Algorithm

NVD (Next-Generation Versatile Disc) is a new generation high-definition player based on Red-light Technology in China. Without the patent control technology of multimedia data, NVD could not move forward.In the current network encryption scheme of the NVD play system, selective encryption algorithm is used to encrypt multimedia data, which would extract multimedia data in proportion as sensitive data and put them in the content server, without encryption for these data. In order to provide patent protection, the sentitive data should be encrypted. Layered encryption algorithms and block encryption algorithms are both part encryption algorithms and their securyity characteristc is competetive. However, the part of data that are required to be encrypted must maintain the same data format, which are easily used by attackers with the weapons of data coding principle.Along with the deep research of DCT in the image processing field and the continuation of video encryption techniques, we find that this encryption algorithm is very suitable for selective encryption of sensitive data processing on the NVD platform. In this scheme, the spatial domain could be transformed to frequency domain by DCT transformation and the coefficient is scrambling encrypted subsequently, which could better reslove the problems of layered and block algorithms.the DCT coefficient encryption algorithm using for encrypting sensitive data is analized and designed. Based on the energy distribution and statistics features of DCT coefficient, the full scrambling algorithm is improved, which processes the coefficient matrix in different segment and increases the compression ratio compared with full scrambling algorithm. The testing results show that sensitive data are successfully encrypted and the decrpted video data could play fluently on the NVD platform. Meanwhile, the system security is greatly improved.