Electronic mail

Abstract: An important issue in multiobjective optimization is the quantitative comparison of the performance of different algorithms. In the case of multiobjective evolutionary algorithms, the outcome is usually an approximation of the Pareto-optimal set, which is denoted as an approximation set, and therefore the question arises of how to evaluate the quality of approximation sets. Most popular are methods that assign each approximation set a vector of real numbers that reflect different aspects of the quality. Sometimes, pairs of approximation sets are also considered. In this study, we provide a rigorous analysis of the limitations underlying this type of quality assessment. To this end, a mathematical framework is developed which allows one to classify and discuss existing techniques.

Abstract: A technique based on public key cryptography is presented that allows an electronic mail system to hide who a participant communicates with as well as the content of the communication - in spite of an unsecured underlying telecommunication system. The technique does not require a universally trusted authority. One correspondent can remain anonymous to a second, while allowing the second to respond via an untraceable return address. The technique can also be used to form rosters of untraceable digital pseudonyms from selected applications. Applicants retain the exclusive ability to form digital signatures corresponding to their pseudonyms. Elections in which any interested party can verify that the ballots have been properly counted are possible if anonymously mailed ballots are signed with pseudonyms from a roster of registered voters. Another use allows an individual to correspond with a record-keeping organization under a unique pseudonym, which appears in a roster of acceptable clients.

Abstract: We study the problem of searching on data that is encrypted using a public key system. Consider user Bob who sends email to user Alice encrypted under Alice’s public key. An email gateway wants to test whether the email contains the keyword “urgent” so that it could route the email accordingly. Alice, on the other hand does not wish to give the gateway the ability to decrypt all her messages. We define and construct a mechanism that enables Alice to provide a key to the gateway that enables the gateway to test whether the word “urgent” is a keyword in the email without learning anything else about the email. We refer to this mechanism as Public Key Encryption with keyword Search. As another example, consider a mail server that stores various messages publicly encrypted for Alice by others. Using our mechanism Alice can send the mail server a key that will enable the server to identify all messages containing some specific keyword, but learn nothing else. We define the concept of public key encryption with keyword search and give several constructions.

Abstract: Part 1 Linking structure and action: problems of explanation in economic sociology the social structure of competition agency as control in formal networks Nadel's paradox revisited - relational and cultural aspects of organizational structure doing your job and helping your friends - universalistic norms about obligations to particular others in networks structural alignments, individual strategies and managerial action - elements towards a network theory of getting things done. Part 2 Different network ties and their implications: centrality and power in organizations the strength of strong ties - the importance of philos in organizations information and search in the creation of new business ventures - the case of the 128 Venture Group complementary communication media - a comparison of electronic mail and face-to-face communication in a programming team face-to-face - making network organizations work. Part 3 Organizational environmental relations as inter-organizational networks: strategic alliances in commercial biotechnology the make-or-cooperate decision in the context of an industry network competitive co-operation in biotechnology - learning through networks? Part 4 Network forms of organizations: the network organization in theory and practice fragments of a cognitive theory of technological change and organizational structure small-firm networks on the limits of a firm-based theory to explain business networks - the Western bias of neoclassical economics the organization of business networks in the United States and Japan. Conclusion: making network research relevant to practice.