On the Security of an MPEG-Video Encryption Scheme Based on Secret Huffman Tables

Abstract

This paper re-studies the security of an MPEG-video encryption scheme based on secret Huffman tables. The present cryptanalysis shows that: 1) the key space of the encryption scheme is not sufficiently large against divide-and-conquer (DAC) ciphertext-only attack; 2) its security against the chosen-plaintext attack is very weak. The insecurity is mainly due to the separated use of different Huffman tables for different sets of syntax elements. A brief discussion on how to improve this MPEG-video encryption scheme is also given