Improved selective encryption techniques for secure transmission of MPEG video bit-streams

This paper presents three new selective encryption techniques for secure transmission of MPEG-I video bit-streams. These techniques maintain higher security levels than previously proposed selective encryption techniques while maintaining reasonable processing times. In the first of these methods, the encryption is applied to the data associated with every n^th I-macroblock. In the second method, the encryption is applied to the headers of all the predicted macroblocks as well as to the data associated with every n^th I-macroblock. In the third method, encryption is applied to every n^th I-macroblock as well as the header of every n^th predicted macroblock. The last method, with n=2, is found to be the most efficient of the three proposed methods. This method achieves a 60-82% reduction in the processing time over “total” encryption, and simulation results show that the encrypted/decoded video is fully disguised