Design and Realization of a New Signal Security System for Multimedia Data Transmission

Abstract

We propose a new signal security system and its VLSI architecture for real-time multimedia data transmission applications. We first define two bit-circulation functions for one-dimensional binary array transformation. Then, we exploit a chaotic system in generating a binary sequence to control the bit-circulation functions defined for performing the successive transformation on the input data. Each eight 8-bit data elements is regarded as a set and is fed into an 8×8 binary matrix being transformed on each row and each column of the matrix by these two bit-circulation functions such that the signal can be transformed into completely disordered data. The features of the proposed design include low computational complexity, regular operations suitable for low-cost VLSI implementation, high data security, and high feasibility for easy integration with commercial multimedia storage and transmission applications. We have performed Matlab simulation to verify the functional correctness of the proposed system. In implementing the system, a low-cost VLSI architecture has been designed, verified, and physically realized based on a 0.35 μm CMOS technology. The implementation results show that the proposed signal security system can achieve 117 Mbytes/s data throughput rate that is fast enough for real-time data protection in multimedia transmission applications

Cryptanalysis of a Multistage Encryption System

“…3) The encryption procedure of each plain-block f (7) (k) is composed of the following four steps: a) Data expansion: get an 8-byte block, f (8) …”

“…, for 12 times with the following parameters in order: (i, j, l) = (0, 4, 3), (1,5,4), (2,6,5), (3,7,6), (0, 2, 7), (1,3,8), (4,6,9), (5,7,10), (0, 1, 11), (2,3,12), (4,5,13), (6,7,14), where Swap w (a, b) outputs (b, a) when w = 1 and (a, b) when w = 0. Denote the permuted 8-byte block by f * (8) (k).…”

“…Property 1: The random masking in Step c) cannot change the differential value, i.e., ∀ k, j, f * * (8) Proof: For the first byte of each 8-byte block, if temp = Open, f (8) 0⊕1 (k, 0) = 0; otherwise, temp is one plain-byte occurring before f (7) (k), which means f…”

“…Apparently, the differential value f (8) 0⊕1 (k, 0) is independent of the value of Open, but uniquely determined by the plaintext and the secret chaotic sequence. Since the other 7 bytes in f (8) 0⊕1 (k) are also independent of Open, this property is thus proved.…”

“…The present paper focuses on cryptanalysis of this new encryption scheme. MES is designed by combining the basic encryption techniques used in previous schemes, such as BRIE [4], RSES/RCES [5], [6] and TDCEA [7], [8], which have been cryptanalyzed in [9]- [11], respectively. Although the combination makes MES securer against the known-plaintext attacks, which can break previous schemes, this paper points out that MES is still insecure against a differential chosen-plaintext/ciphertext attack.…”