Shiguo Lian

A novel image encryption scheme based-on JPEG encoding

Image encryption is a suitable method to protect image data. The encryption algorithms based on position confusion and pixel substitution change compression ratio greatly. In this paper, an image encryption algorithm combining with JPEG encoding is proposed. In luminance and chrominance plane, the DCT blocks are confused by pseudo-random SFCs (space filling curves). In each DCT block, DCT coefficients are confused according to different frequency bands and their signs are encrypted by a chaotic stream cipher. The security of the cryptosystem against brute-force attack and known-plaintext attack is also analyzed. Experimental results show that, the algorithm is of high security and low cost. Whats more, it supports direct bit-rate control or recompression, which means that the encrypted image can still be decrypted correctly even if its compression ratio has been changed. These advantages make it suitable for image transmission over network.

Secure hash function based on neural network

Abstract A hash function is constructed based on a three-layer neural network. The three neuron-layers are used to realize data confusion, diffusion and compression, respectively, and the multi-block hash mode is presented to support the plaintext with variable length. Theoretical analysis and experimental results show that this hash function is one-way, with high key sensitivity and plaintext sensitivity, and secure against birthday attacks or meet-in-the-middle attacks. Additionally, the neural networks property makes it practical to realize in a parallel way. These properties make it a suitable choice for data signature or authentication.

A selective image encryption scheme based on JPEG2000 codec

In this paper, a novel image encryption scheme based on JPEG2000 is proposed, which encrypts some sensitive frequency subbands, bit-planes or encoding-passes selectively and partially. It is secure against such attack as known-plaintext attack or replacement attack. It is of low cost, keeps file format and compression ratio unchanged, supports direct bit-rate control, and does not degrade the original error-robustness. These properties make it suitable for real-time applications with direct bit-rate control requirement, such as web imaging, image communication, mobile or wireless multimedia, and so on.

Efficient video encryption scheme based on advanced video coding

A video encryption scheme combining with advanced video coding (AVC) is presented and analyzed in this paper, which is different from the ones used in MPEG1/2 video encryption. In the proposed scheme, the intra-prediction mode and motion vector difference are encrypted with the length-kept encryption algorithm (LKE) in order to keep the format compliance, and the residue data of the macroblocks are encrypted with the residue data encryption algorithm (RDE) in order to keep low cost. Additionally, a key distribution scheme is proposed to keep the robustness to transmission errors, which assigns sub-keys to different frames or slices independently. The encryption scheme’s security, time efficiency and error robustness are analyzed in detail. Experimental results show that the encryption scheme keeps file format unchanged, is secure against replacement attacks, is efficient in computing, and is robust to some transmission errors. These properties make it a suitable choice for real-time applications, such as secure IPTV, secure videoconference or mobile/wireless multimedia, etc.

A fast video encryption scheme based-on chaos

Video encryption is a suitable method to protect video data. There are some disadvantages in the algorithms proposed before. In this paper, we propose a novel fast MPEG video encryption algorithm, which encrypts run length codes with chaotic run-length encryption algorithm (CREA), encrypts the signs of motion vectors with security-enhanced chaotic stream cipher (SECSC) and distributes keys with chaotic key distributor (CKD) at the same time. Its security, compression ratio and computational complexity are analyzed in details. Experimental results show that, the algorithm has less effect on compression ratio than the algorithms confusing DCT coefficients do, does not change file format, and is of low cost. Thus, it is suitable for secure video encoding with real-time requirement.

A fast video encryption scheme suitable for network applications

Video encryption is suitable for video protection. A video encryption scheme combining an encryption process with the MPEG2 encoding process is presented. It encrypts I-frames with color plane confusion, coefficient confusion and sign encryption, encrypts the intra-macroblocks in P/B-frames with coefficient confusion and sign encryption, and encrypts the inter-macroblocks with motion vector encryption. Theoretical analysis and experimental results show that the scheme is secure, of low cost, supports direct bit-rate control and is more robust to transmission errors. These properties make it suitable for multimedia applications with real-time operation and a direct bit-rate control requirement, such as video conference, multimedia network, wireless or mobile multimedia, and so on.

A Fast MPEG4 Video Encryption Scheme Based on Chaotic Neural Network

In this paper, a fast video encryption scheme is proposed, which combines encryption process with MPEG4 encoding. This scheme encrypts video object layers (VOLs) selectively. That is, the motion vectors, subbands, code blocks or bit-planes are encrypted partially. A stream cipher based on chaotic neural network is used in all these encryption processes, which is of high security and low cost. This encryption scheme keeps compression ratio and file format unchanged, supports direct bit-rate control, and keeps the error-robustness unchanged. These properties make it suitable for real-time applications, such as video-on-demand system, video-conference system, mobile or wireless multimedia, and so on.

Perceptual MPEG-4 video encryption and its usage in video-on demand systems

In thi.s paper, a perceptual encpption algorithm is proposed ,fkr MPEG4 encoded videos. The algaru,.itlim e n o y t s MPEG4 stream seledivelv arid progrecsivels under the control oJqr~ulIr?, farttir. Bared on the encryption algorithm. a smitre video-oil-demand svstem is lmsented. Tlieoretical arialvsis and e-rpwimental resu1t.s show !hat. die encvption algorithm is of high secnri~v, law cost, and si1pport.y direct hit-rate control. and the video-on-demand syteni is of higlier .secirriw, andsupports more applications. Index Terms Video encryption, perceptual cryptography, Video-On-Demand system.

Lightweight MPEG4 video encryption algorithm suitable for network transmission

In this paper, a video encryption algorithm based on MPEG4 codec is proposed, which combines encryption process with MPEG4 compression process. This algorithm is composed of two parts: VOP (Video Object Plane) encryption and VOL (Video Object Layer) encryption. In VOP encryption, the intra-encoded VOP is encrypted by inter-block permutation, the intra-encoded code blocks are encrypted by bit-plane permutation and coefficient sign encryption, and the other code blocks are encrypted by motion vector encryption. In VOL encryption, the basic VOLs are encrypted while others left unchanged. It can obtain high speed, for only parts of VOLs are encrypted. And it supports direct bit-rate control, which means that the encrypted images can also be decrypted correctly after recompression or bit-rate conversion. Whats more, it is more robust to transmission errors than traditional ciphers since the errors causing in the encrypted bit-stream cannot spread out. These properties make it suitable for secure multimedia transmission over network, such as Video-on-Demand systems, multimedia communication networks, mobile multimedia or wireless multimedia networks, and so on.