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The Domain Name System (DNS) is the most crucial infrastructure for mapping human-readable host names to the corresponding IP addresses and providing the routing information of Email. Comparing with the top-level domains (TLD) such as the root servers, the local authoritative servers are more vulnerable to device failures and malicious attacks. This paper described the existence condition of authoritative servers and presented a novel domain measurement tool named DNSAuth to collect the information of local authoritative servers automatically. Experiments to the real-life authoritative servers were conducted which highlighting three important aspects: the distribution, the geographic location and their impacts on performance and security. According to five representative attributes, the authoritative servers of China Top100 websites are evaluated and the result shows that only 32% of all the servers act preferably in performance and security. [ABSTRACT FROM AUTHOR]

The (Distributed) Denial of Service (DoS/DDoS) attacks have become the main devastating threats to web services, and generally, the Probing attacks are the prior steps of DoS/DDoS attacks. To achieve the aim of the information assurance, an intrusion detection mechanism based on the Vector Quantization (VQ) technique is proposed for countering DoS/DDoS and Probing attacks in this paper. The normal network traffic usage profile can be modeled and represented by the codebook of VQ from which the abnormal behavior deviation of TCP traffic can be measured quantitatively well. In data processing, according to the characters of DoS/DDoS and Probing attacks, we implement the novel feature extraction of TCP flow state. We apply the detection mechanism to DARPA Intrusion Detection Evaluation Data Set. It is shown that the network attacks are detected with more efficiency and relatively low false alarms. [ABSTRACT FROM AUTHOR]

Network traffic burst becomes a threat to network security. In this paper, a decomposition based method is presented for network burst traffic realtime prediction, in which, by passing smoothing filter, network traffic is decomposed into smooth low frequency traffic and high frequency traffic to make prediction respectively, and then a superposition result of the predictions is yielded. Based on LMS algorithm, an improvement of LMS predictor by adjusting prediction according to prediction errors (EaLMS, Error-adjusted LMS) is proposed to process the low frequency traffic, and a simple method of linear combination is presented to predict the high frequency traffic. The experiment results using real network traffic data shows, compared with traditional LMS, the prediction method based on decomposition obviously shorted the prediction delay and reduced the prediction error during traffic burst, while it also improves the global prediction. [ABSTRACT FROM AUTHOR]

Advance Video Coding standard (AVS) [1] is the standard for compression and decompression in digital audio and video multimedia. The AVS Working Group was approved by the Science and Technology Department of Ministry of Information Industry of china on June 2002. AVS has employed a 4-tap interpolation FIR filter in its motion compensation (MC) part for high coding efficiency. But it is accompanied by increasing the complexity in calculation and memory access. And this problem makes MC one of the bottlenecks in the AVS system΄s VLSI implementation, especially for SDTV or HDTV which aggravate the problem heavily. Unfortunately, most FIR filter [3-5] have too low of input bandwidth to deal with it. In this paper, an efficient architecture for MC interpolation is described, and experimental results show that this architecture satisfies AVS decoder applications such as SDTV or HDTV. [ABSTRACT FROM AUTHOR]

Sample interpolation which has a computationally expensive finite impulse response (FIR) digital filter is one of the key modules in MPEG-4 Advanced Simple Profile (ASP). Normal FIR architectures have low efficiency on its implementation due to the special input data stream. In this paper, based on a pure systolic FIR, the efficient VLSI architecture for the sample interpolation has been implemented. Experimental result shows that the efficiency of proposed architecture is three times higher than normal ones, and it satisfies the applications such as MPEG-4 ASP. [ABSTRACT FROM AUTHOR]

Distributed denial-of-service(DDoS) attacks have recently emerged as a major threat to the security and stability of the Internet. As we know, traffic bursts always go with DDoS attacks. Detecting the network traffic bursts accurately in real-time can catch such attacks as quickly as possible. In this paper, we categorize the traffic bursts into three kinds: Single-point-burst, Short-flat-burst and Long-flat-burst, and propose a network traffic burst detecting algorithm (BDA-CWT) based on the continuous wavelet transform. In this algorithm, we use a slip window to analyze the traffic data uninterruptedly to detect the Short-flat-burst or the Long-flat-burst, which always represents DDoS attacks. Our experiment has demonstrated that the proposed detection algorithm is responsive and effective in curbing DDoS attacks, in contrast with the discrete wavelet transform and traditional methods (N-point-average and gradient). [ABSTRACT FROM AUTHOR]