Cryptanalysis of Some Multimedia Encryption Schemes

Abstract

Abstract-Encryption is one of the fundamental technologies that is used in digital rights management. Unlike ordinary computer applications, multimedia applications generate large amounts of data that has to be processed in real time. So, a number of encryption schemes for multimedia applications have been proposed in recent years.We analyze the following proposed methods for multimedia encryption: key-based multiple Huffman tables (MHT), arithmetic coding with key-based interval splitting (KSAC) and randomized arithmetic coding (RAC). Our analysis shows that MHT and KSAC are vulnerable to low complexity known-and/or chosen-plaintext attacks. Although we do not provide any attacks on RAC, we point out some disadvantages of RAC over the classical compress-then-encrypt approach.

A New Framework for Encryption and Authentication of Multimedia Data

“…To do this, if the i th bit of the key is 1, the labels of two branches of the i th node in the Huffman tree are exchanged, otherwise kept unchanged. Thus, the number of possible values of an n-bit code of a symbol increases to 2 n [5,10]. Since, there is no additional computation overhead for this algorithm compared with the standard Huffman coding, MHT based system is computationally fast [9].…”

“…In [10], it is proved that the MHT based encryption scheme is vulnerable to known plaintext attack. They have considered two key possibilities; long-term keys and premessage keys.…”

“…In the literature, it is proved that the MHT based encryption system is vulnerable to known plaintext attack [9][10] and ciphertext only attack [11]. Thus, the MHT based encryption system alone is unable to provide complete level of end to end security and making modifications to Huffman coding must be done with extreme care without affecting its compression performance and simplicity.…”

A differential cryptanalysis of Yen–Chen–Wu multimedia cryptography system

“…Then, perform the byte swapping operation for the following 32 values of (i, j, l) one after another: (0,8,4), (1,9,5), (2,10,6), (3,11,7), (4,12,8), (5,13,9), (6,14,10), (7,15,11), (0,4,12), (1,5,13), (2,6,14), (3,7,15), (8,12,16), (9,13,17), (10,14,18), (11,15,19), (0,2,20), (1,3,21), (4,6,22), (5,7,23), (8,…”

“…Due to the subtle similarity between chaos and cryptography, some of multimedia encryption schemes were designed based on one or more chaotic systems [3,4,5,8,9,11]. Meanwhile, a lot of cryptanalytic work has also been reported, showing that many encryption schemes were not designed carefully and are prone to various kinds of attacks [12,13,14,15,16,17,18,19,20,21,22,23].…”