加强IDC网络安全 实现信息社会和谐

本文分析了当前IDC网络环境中存在的安全隐患及网络攻击的手段,针对IDC中心的网络实际情况,从理论上提出了网络安全设计的原则、安全防御的策略和措施,列举了解决网络安全问题的相关技术,探讨建立综合性的网络安全防御系统确保网络及信息的安全。     

基于IPv6网络安全研究

随着网络人数的不断增加,IPv6取代IPv4只是时间的问题,我们首先介绍了IPv6优于IPv4的特点,它之所以成为下一代网络发展的必然趋势的原因。其次介绍了在IPv6下,网络安全比现在存在哪些优势和技术,从而也带来了哪些新的安全隐患。最后我们举例说明在IPv6下如何实现网络入侵的流程。     

Efficient chosen-ciphertext secure certificateless threshold key encapsulation mechanism

As a practical extension of our previous work on certificateless threshold cryptosystem, this paper proposes the first direct certificateless threshold key encapsulation mechanism that inherits the same trust level of the original scheme and removes the length limitation of a traditional public key encryption. Security against threshold chosen-ciphertext attacks are proved in a random oracle model under a new assumption. It tolerates the Type I adversary that can replace public keys and the Type II adversary that has access to the system’s master key. The implied encapsulation scheme is very efficient when compared to the most efficient schemes in a traditional public key cryptosystem, and it is slightly more efficient in terms of key length and encapsulation speed when compared to the identity-based cryptosystems that have the same ciphertext overhead. Finally, we describe several potential modifications of our scheme.     

Continuous wavelet analysis for the detection of green attack damage due to mountain pine beetle infestation

Mountain pine beetle (Dendroctonus ponderosae Hopkins) is the most destructive insect infesting mature pine forests in North America and has devastated millions of hectares of forest in western Canada. Past studies have demonstrated the use of multispectral imagery for remote identification and mapping of visible or red attack damage in forests. This study aims to detect pre-visual or green attack damage in lodgepole pine needles by means of hyperspectral measurements, particularly via continuous wavelet analysis. Field measurements of lodgepole pine stands were conducted at two sites located northwest of Edmonton, Alberta, Canada. In June and August of 2007, reflectance spectra (350-2500 nm) were collected for 16 pairs of trees. Each of the 16 tree pairs included one control tree (healthy), and one stressed tree (girdled to simulate the effects of beetle infestation). In addition, during the period of June through October 2008, spectra were collected from 15 pairs of control- and beetle-infested trees. Spectra derived from these 31 tree pairs were subjected to a continuous wavelet transform, generating a scalogram that compiles the wavelet power as a function of wavelength location and scale of decomposition. Linear relationships were then explored between the wavelet scalograms and chemical properties or class labels (control and non-control) of the sample populations in order to isolate the most useful distinguishing spectral features that related to infested or girdled trees vs. control trees.A deficit in water content is observed in infested trees while an additional deficit in chlorophyll content is seen for girdled trees. The measurable water deficit of infested and girdled tree samples was detectable from the wavelet analysis of the reflectance spectra providing a novel method for the detection of green attack. The spectral features distinguishing control and infested trees are predominantly located between 950 and 1390 nm from scales 1 to 8. Of those, five features between 1318 to 1322 nm at scale 7 are consistently found in the July and August 2008 datasets. These features are located at longer wavelengths than those investigated in previous studies (below 1100 nm) and provide new insights into the potential remote detection of green attack. Spectral features that distinguish control and girdled trees were mostly observed between 1550 and 2370 nm from scales 1 to 5. The differing response of girdled and infested trees appears to indicate that the girdling process does not provide a perfect simulation of the effects caused by beetle infestation.It remains to be determined if the location of the 1318-1322 nm features, near the edge of a strong atmospheric water absorption band, will be sufficiently separable for use in airborne detection of green attack. A plot comparing needle water content and wavelet power at 1320 nm reveals considerable overlap between data derived from both infested and control samples, though the groups are statistically separable. This obstacle may preclude a high accuracy separation of healthy and infected single individuals, but establishing threshold identification levels may provide an economical, efficient and expeditious method for discriminating between healthy and infested tree populations.     

浅谈黑客技术及其对策

本文通过对黑客起源及其文化的认识来分析黑客技术的发展,同时也针对当前一些主要的黑客攻击手段提出了防御的对策。     

基于分层网格的Sybil攻击检测方案

在无线传感器网络(WSN)中,Sybil攻击的危害大且难于检测。针对该问题,提出一种基于分层网格的Sybil攻击检测方案。根据Sybil节点身份的多变性,采用分层网格技术初步确定其物理位置,通过网格节点间的密钥技术确认Sybil节点。仿真结果表明,该方案的检测性能高、内存使用率低、网络扩展性强,且适用于WSN的多跳传输。     

基于SOAP消息的过度加密攻击检测算法

分析Web服务中的过度加密攻击场景、攻击特点以及SOAP消息特征,提出一种基于简单对象访问协议消息(SOAP)消息的过度加密攻击检测算法。通过检测标签ReferenceList的属性个数统计SOAP消息的加密次数,并将统计出的加密次数与预先设定的阈值进行比较,从而判断是否存在过度加密攻击。在.net WSE安全平台下验证了该检测算法的有效性。     

具有最大代数免疫度的奇数元布尔函数的构造

构造一个具有最大代数免疫度的奇数元布尔函数等价于在某一已知矩阵中寻找一个可逆子矩阵。如何在这一矩阵中有效地寻找可逆子矩阵仍然是一个难题。针对上述问题研究矩阵的性质,简化矩阵的刻画方式,给出构造最大代数免疫度的奇数元布尔函数的构造方法。构造时只需对低维数的向量进行操作,避免了子矩阵可逆性的判断,能够有效地构造具有最大代数免疫度的奇数元布尔函数。     

基于预测模型的最佳进攻球员和进攻点选择

以FIRA SimuroSot5v5仿真平台为背景,针对策略中如何最大化进攻威胁的问题,提出一种基于预测模型的最佳进攻球员和进攻点选择方法。对机器人和球的运动规律进行建模,根据建立的预测模型确定机器人的有效进攻时间,计算可进攻球员和可进攻点,并对每个可进攻球员及进攻点进行进攻威胁度评估,得到最佳进攻球员和最佳进攻点。仿真实验验证了该方法的有效性。     

Shellcode静态检测技术研究

缓冲区溢出攻击是网络安全的重大威胁,事先检测是否存在Shellcode是对抗缓冲区溢出攻击的有效手段。从Shellcode构成和特征出发,分类研究各种Sheltcode静态检测技术,分析比较它们的优缺点,在此基础上提出了一种检测方案并实现了一个原型系统。