基于网络测量系统的SYNFlooding攻击防御机制

探索了SYN Flooding攻击的特征,提出了判断攻击发生的关键指标。介绍了网络测量系统的架构,详细阐述了具有服务保护与攻击消除功能的检测方法、攻击源追踪方法。最后分别给出了验证检测机制和追踪机制的实验与结果。     

浅论网站交叉脚本攻击和SQL插入攻击

网站交叉脚本攻击(CROSS-SITESCRITINGATTACK)和SQL(STRUCTUREDQUERYLANGUAGE)插入(SQLINJECTION)是黑客经常采用的攻击互联网应用程序(WEB-BASEDAPPLICA TIONS)的两种有效手段.网站交叉脚本攻击可以影响运行于目前市场上所有厂家的互联网服务器程序之上运用了动态页面产生技术(如ASP或JSP)的互联网应用程序.相对而言SQL插入攻击的原理较简单,但它仍可造成资源和劳动力的巨大损失;该文全面地介绍了网站交叉脚本攻击和SQL插入攻击的工作原理、可能后果及有效的防治方法.     

Chlorine Truck Attack Consequences and Mitigation

We develop and apply an integrated modeling system to estimate fatalities from intentional release of 17 tons of chlorine from a tank truck in a generic urban area. A public response model specifies locations and actions of the populace. A chemical source term model predicts initial characteristics of the chlorine vapor and aerosol cloud. An atmospheric dispersion model predicts cloud spreading and movement. A building air exchange model simulates movement of chlorine from outdoors into buildings at each location. A dose‐response model translates chlorine exposures into predicted fatalities. Important parameters outside defender control include wind speed, atmospheric stability class, amount of chlorine released, and dose‐response model parameters. Without fast and effective defense response, with 2.5 m/sec wind and stability class F, we estimate approximately 4,000 (half within ～10 minutes) to 30,000 fatalities (half within ～20 minutes), depending on dose‐response model. Although we assume 7% of the population was outdoors, they represent 60–90% of fatalities. Changing weather conditions result in approximately 50–90% lower total fatalities. Measures such as sheltering in place, evacuation, and use of security barriers and cryogenic storage can reduce fatalities, sometimes by 50% or more, depending on response speed and other factors.     

有限域上Chebyshev映射的周期性分析

基于有限域上Chebyshev映射的公钥密码系统的安全性直接取决于Chebyshev映射的周期性。利用矩阵变换讨论有限域ZN上Chebyshev映射的周期性问题，并给出一种快速的寻找周期的方法，从而使得对有限域上Cheyshev公钥加密方案的攻击成为可能。     

From the Trenches: Attacking First-Time Women Candidates for Congress

SUMMARY

Women candidates in the United States no longer enjoy a “compassion advantage” when running against male candidates. First-time women congressional candidates in open seats are especially vulnerable to excessively aggressive negative attacks from their male opponents because (1) high-tech message delivery systems make attack campaigning easy; (2) attack messages attract more attention than positive messages and get the voters to pay attention; (3) large sums of money can be raised for these attacks from national interest groups by emphasizing the national importance of Congressional races; (4) first-time women candidates who are not elected officials do not have the public record and visibility that could insulate them from the abusive distortions of their views and even of their physical appearance; (5) the press does a poor job of covering suburban-rural races and independent fact checking is virtually nonexistent; and (6) since 9/11, terrorism has become a major issue and women are apt to be portrayed as too inexperienced to be trusted with protecting the national defense.     

Should Cities Invest in Sheltering‐in‐Place Measures Against Chlorine Truck Attacks by Terrorists?

After an intentional release of chlorine in an office district, public responses such as sheltering‐in‐place could save many lives if rapid enough. However, previous work does not estimate how fast and effective such responses would be for several possible investments in attack detection, public alert, and building ventilation, nor whether such measures would be cost effective. We estimate public response times with investment options in place, and resulting changes in fatalities as well as system costs, including false alarm costs, and cost effectiveness in terms of cost per net death avoided. The measures do have life‐saving potential, especially if all response times are at or near the lower limits of the ranges assumed in this article. However, due to uncertainties, it is not clear that responses would be rapid enough to save many people. In some cases total fatalities would increase, since sheltering after chlorine vapor has already entered buildings can increase occupants’ chlorine exposure. None of the options considered have median cost per statistical life saved meeting a cost‐effectiveness threshold of $6.5 million across all of the chlorine exposure dose‐response and ingress‐delay models considered here, even if there were one attack per year in the area covered by the system. Given these and other issues discussed in this article, at this point investments to improve sheltering‐in‐place capability appear not to be robust strategies for reducing fatalities from chlorine attack in an office district.     

激进模式下对IKEv1的中间人攻击分析

分析了对IKEv1的一种中间人攻击方法,该方法基于IKEv1密钥交换在预共享密钥认证机制下的激进模式。实施中间人攻击的步骤是首先利用IKEv1的离线口令穷举获取预共享密钥,获得预共享密钥后,把Diffie-Hellman(DH)中间人攻击原理应用于IKEv1的激进模式,实现对IKEv1的中间人攻击。通过分析该模式的中间人攻击原理,得出了对IKEv1的激进模式进行中间人攻击的条件、实施方法并评估了其对IPsec的危害性。由于该模式存在用户名枚举漏洞,攻击者可以离线穷尽预共享密钥,在现实中IKE中间人攻击的威胁是存在的,建议在使用IPsecVPN时不使用激进模式的密钥协商,并加强中间路由器的安全防护。     

谈进攻假动作在篮球比赛中的运用

本文通过对现代篮球运动中防守技术发展特点的分析 ,指明假动作在蓝球比赛中应随机应变 ,不可滥用才能事半功倍。     

The Economic Impacts of a Terrorist Attack on the U.S. Commercial Aviation System

We use data on air passenger travel expenditures per passenger as well as statistical analysis of the air traffic lost for the two-year aftermath of the September 11, 2001, attacks to estimate direct demand losses for air transportation services. These are used along with a national input-output model to assess the full costs of these losses. Depending on assumptions made, the full losses to the U.S. economy were between $214.3 and $420.5 billion. These estimates are similar to those from other studies of such an event, and suggest that the high costs of effective countermeasures may be justified.     

政治发展还是“政治退却”——新中国政治发展战略退却思问

政治发展是不同类型国家都面临的问题。我国政治发展目标是人民民主。与改革开放三十年的辉煌成就相比,中国政治发展在实践和理论层面上都存在一定滞后性,这需要从新中国60年的发展历程中进行反思。与中国改革开放之前的“政治战略进攻”相比较,用“政治发展战略退却”来描述当今更为合适。政治战略进攻,脱离了中国社会历史现实和国情,是一种超越现实的、罗曼蒂克式的政治发展;从浪漫主义的政治发展经过改革、退却到不合格的不完全的社会主义政治,是一种趋向于现实主义的政治发展;从多元政治主体关系中谋求以社会主义政治为主导和定向的政治变迁,是一种理想主义与现实主义相结合的和合主义的中国式的政治发展战略。