Search

In order to solve the poor robustness of software watermarking and the low execution efficiency of watermarking sharing algorithm, this paper proposed a sharing software watermarking scheme based on chaotic optimization. The scheme took advantage of chaos system, matrix partition and chaotic scrambling the watermarking information to form sharing watermarking. When watermarking was embedded, using DPPCT topology graph encode the sharing watermarking, then putting the hash value of the watermarking information into the info field of each DPPCT. After the watermarking embedded, using chaotic encryption to protect all code and prevent reverse engineering and other methods to attack the software watermarking. Theoretical analysis and experimental results show that the scheme can effectively resist various semantics preserving transformation attacks, decrease the program load and improve robustness and execution efficiency of the watermarking. [ABSTRACT FROM AUTHOR]

Forwarded information in the second hop was vulnerable to be eavesdropped in traditional methods, this paper proposed a group cooperation method for physical layer security based on cooperated beamforming. Firstly, it classified relays in two groups, cooperative jamming group and cooperative relaying group, based on the cascaded channel of sending-relaying-receiving. Secondly, it cooperated the two groups by decode-and-forward strategy and noise-and-forward strategy to improve the maximum secrecy rate. It classified the relays into collaboration jamming group and collaboration relaying group. Finally, it optimized power allocation to achieve maximize secrecy rate under the limited power. Simulation results show that the maximum secrecy rate in the proposed method is more high than the referenced method, and keep upgrading with the increasing of the power. Compared with the referenced method, the method proposed can promote 0. 6 bps/Hz performance. Therefore, this scheme can effectively improve the security of cooperative relay system. [ABSTRACT FROM AUTHOR]

In high-bitrate live system, due to existing light signature multicast authentication scheme's high overhead, this paper proposed an unequal authenticity protection method. This method weighted packet authentication importance by frame's dependencies in video coding, it constrainted packet security level and the range of evidence, differed evidence portion by authentication importance and evidence matrix consumption, which optimized evidence consumption and the loss of abnormal authentication. The simulation results show that given packet's amortized security level is 2, communication and computation cost decline by 67. 0% and 68. 3%, meets the needs of authenticating 10 Mbps video multicast stream. [ABSTRACT FROM AUTHOR]

According to the flexible flow shop scheduling problem with blocking and no-wait constraints, this paper proposed a discrete particle swarm optimization (DPSO) algorithm. Based on the permutation based encoding scheme, it designed a forward-iterative algorithm for decoding and obtaining the objective, used DPSO for global optimization, introduced iterated greedy (IG) algorithm to improve the particles' local searching ability. Besides, it put forward the first release first (FRF) and first complete first (FCF) policies for selecting the processing machines. Experiment results show that the proposed method to solve the flexible flow shop scheduling problem with mixed constraints is feasible and effective. [ABSTRACT FROM AUTHOR]

This paper proposed a parallel video coding scheme based on MapReduce. It divided the input video sequence into segments and mapped to multiple computers in the form of tasks. After that, it encoded all these tasks in parallel at different computer nodes to achieve better encoding speed. In order to minimize the makespan of a given tasks set and balance the system load, this paper proposed a LBMM algorithm according to the computing capacity and the coding charactertics. The simulated results show the proposed parallel video coding system greatly improves the big volumn video sequence coding efficiency, reduces the average job response time. The LBMM algorithm outperforms Min-Min (minimal-minimal complete time) algorithm and RR (round robin) algorithm using in CloudSim. [ABSTRACT FROM AUTHOR]

In order to improve the security of secret image transmission, this paper put forward a kind of image encryption scheme based on hyper-chaotic sequences. Firstly, it added plaintext pixel information to the transformation of each element of hyper-chaotic sequences which resulted in both key sensitivity and plaintext sensitivity. Then, it shuffled and encrypted the plaintext pixels according to the separation scrambling key sequences and the gray replacement key sequences pixel by pixel. The simulation results show that the gray distribution of encrypted image is balanced with its cipher-text sensitive to plain-text and key, and it is secure with strong resistibility to various attacks, such as statistical, exhaustive and differential attacks, verifying the feasibility of this scheme. [ABSTRACT FROM AUTHOR]

This paper analyzed the security of a blind signature scheme and showed that it was insecure against the public key replacement attack in certificateless cryptosystems, the adversary could replace the users' public key to forge the signature and presented the forgery attack method. Based on this attack and combined with the constructor of blind signature and the selection methods of blind factor, this paper gave an improved scheme and analyzed the blindness, unlinkability, non-forgery and efficiency The results show that the new scheme is more secure and efficient. [ABSTRACT FROM AUTHOR]

Through the cryptanalysis of a proxy blind signature scheme based on DLP proposed by He Jun-jie, this paper found that this scheme can cause the public replacement attack. To avoid these attacks, this paper proposed a new improved scheme. Analysis result shows that the new improved scheme can resist the original signer's public key replacement attack. It satisfies all the security requirements of proxy blind signature based on the DLP problems and improve the computation efficiency. [ABSTRACT FROM AUTHOR]

This paper proposed a mobile protocol for IPv6 -based urban vehicular networks. The protocol created the urban vehicular network architecture. In the protocol, when a vehicle joint an urban vehicular network, it acquired its home address. During the mobility process, a vehicle was always identified by its home address and did not need to be configured with a care-of address, so the care-of address configuration cost and delay were avoided. As a result, it reduced the mobility handover cost and delay. The protocol did not involve a vehicle in the mobility handover process, so it avoided the extra mobility handover cost and delay caused by the packet loss due to a vehicle's high speed. The simulation data show that the protocol has better performance. [ABSTRACT FROM AUTHOR]