Protection Against Spam Using Pre-Challenges

Abstract: Spam turns out to be an increasingly serious problem to email users. A number of anti-spam schemes have been proposed and deployed, but the problem has yet been well addressed. One of those schemes is challenge-response, in which a challenge is imposed on an email sender. However, such a scheme introduces new problems for the users, e.g., delay of service and denial of service attacks. In this paper, we introduce a pre-challenge scheme that avoids those problems. It assumes each user has a challenge that is defined by the user himself/herself and associated with his/her email address, in such a way that an email sender can simultaneously retrieve a new receiver's email address and challenge before sending an email in the first contact. Some new mechanisms are employed to reach a good balance between security against spam and convenience to email users

Let Your CyberAlter Ego Share Information and Manage Spam

Almost all of us have multiple cyberspace identities, and these {\em cyber}alter egos are networked together to form a vast cyberspace social network. This network is distinct from the world-wide-web (WWW), which is being queried and mined to the tune of billions of dollars everyday, and until recently, has gone largely unexplored. Empirically, the cyberspace social networks have been found to possess many of the same complex features that characterize its real counterparts, including scale-free degree distributions, low diameter, and extensive connectivity. We show that these topological features make the latent networks particularly suitable for explorations and management via local-only messaging protocols. {\em Cyber}alter egos can communicate via their direct links (i.e., using only their own address books) and set up a highly decentralized and scalable message passing network that can allow large-scale sharing of information and data. As one particular example of such collaborative systems, we provide a design of a spam filtering system, and our large-scale simulations show that the system achieves a spam detection rate close to 100%, while the false positive rate is kept around zero. This system has several advantages over other recent proposals (i) It uses an already existing network, created by the same social dynamics that govern our daily lives, and no dedicated peer-to-peer (P2P) systems or centralized server-based systems need be constructed; (ii) It utilizes a percolation search algorithm that makes the query-generated traffic scalable; (iii) The network has a built in trust system (just as in social networks) that can be used to thwart malicious attacks; iv) It can be implemented right now as a plugin to popular email programs, such as MS Outlook, Eudora, and Sendmail.Comment: 13 pages, 10 figure

Preemption of State Spam Laws by the Federal Can-Spam Act

Unsolicited bulk commercial email is an increasing problem, and though many states have passed laws aimed at curbing its use and abuse, for several years the federal government took no action. In 2003 that changed when Congress passed the CAN-SPAM Act. Though the law contains many different restrictions on spam messages, including some restriction of nearly every type that states had adopted, the Act was widely criticized as weak. Many of the CAN-SPAM Act\u27s provisions are weaker than corresponding provisions of state law, and the Act preempts most state spam laws that would go farther, including two state laws that would have banned all spam. Despite these weaknesses, this Comment argues that when properly interpreted the CAN-SPAM Act leaves key state law provisions in force, and accordingly is stronger than many spam opponents first thought. First, the law explicitly preserves state laws to the extent that they prohibit falsity or deception in any portion of a commercial electronic mail message or information attached thereto. Though Congress was primarily concerned with saving state consumer protection laws, this language can be applied much more broadly. Second, the law is silent on the question of state law enforcement methods. State enforcement can be, and frequently is, substantially stronger than federal enforcement, which is largely limited to actions by the federal government, internet service providers, and state agencies. The Comment concludes by arguing that this narrow interpretation of its preemption clause is most consistent with the CAN-SPAM Act\u27s twin policy goals. By limiting the substantive provisions states may adopt, the Act prevents states from enacting inconsistent laws and enforces a uniform national spam policy. At the same time, narrowly interpreting the preemption clause permits states to experiment within the limits of that policy, in hopes of finding the most effective set of spam regulations

Promises, Promises

As host of the Olympic Games, China seeks to increase national economic and socialdevelopment and "display to the world a new image of China", and presents the Games as an opportunity to foster democracy, improve human rights and integrate China with the rest of the world. In its Olympic Action Plan promulgated in 2002, China outlined the phases of construction in the run up to the 2008 Games, and the standards to which it would hold itself in the governance and construction of venues, impact on Beijing's environment, increasing social and economic development and providing China's citizenry with greater access to information and technology.The goals and specific commitments that the government has adopted not only have implications for the smooth and successfuloperation of the Olympic Games, but also have the potential to impact on a number of China's international obligations, including its human rights obligations.Despite human rights-related commitments as diverse as transparency and accountability, access to information and freedom of the press, poverty alleviation, an improved standard of living for all people, and compensation for evictions and health issues, the record to date raises serious compliance issues