An efficient authentication scheme for high efficiency video coding/H.265

In this paper, a semi-fragile authentication scheme for high efficiency video coding is proposed. In this scheme, 4 × 4 intra luma transform blocks of I-frames are divided into two disjoint subsets. One subset is used for authentication code generation and another subset is used for embedding the generated code. From these subsets, blocks are selected on the basis of the quality and robustness thresholds. These thresholds are calculated at runtime by using a low-complexity spatial analysis. The authentication code is generated based on the relationship between number of positive and negative quantized discrete sine transformed coefficients in a block. The generated authentication code is embedded by altering the magnitudes of quantized discrete sine transformed coefficients during encoding of the video sequence. The process of authentication has low complexity as embedded authentication code can be extracted and verified without full decoding of the encoded bit-stream. Experimental results show that the proposed scheme is efficient in terms of imperceptibility, increase in bit-rate, computational complexity, robustness to re-compression, frame dropping, noise attacks and fragile to malicious attacks.