Encryption of MPEG using Error Propagation by a Receiver

According to increased multimedia data(i.e., MPEG video stream) in mobile application, protecting data becomes an important problem in the multimedia data delivery. SECMPEG is a selective encryption approach for protecting multimedia data. However, the computational overhead of SECMPEG's security level 3 is quite large because it encrypts the whole I-frames whose size is relatively larger than P/B-frames. Therefore, we need to analyze the characteristics of MPEG2 standard and derive an effective encryption of the I-frames. In this paper, we propose a slice-level, selective encryption approach by using the error-propagation characteristics of I-frames by a receiver. Our experimental results show that the proposed approach can reduce the execution time of SECMPEG's security level 3 by a factor of 30 without degradation of the security.