The free flow of information is the feature that has made peer-to-peer information sharing applications popular. However, this very feature holds back the acceptance of these applications by the corporate and scientific communities. In these communities it is important to provide confidentiality and integrity of communication and to enforce access control to shared resources. We present a number of security mechanisms that can be used to satisfy these security requirements. Our solutions are based on established and proven security techniques and we utilize existing technologies when possible. As a proof of concept, we have developed an information sharing system, called scishare, which integrates a number of these security mechanisms to provide a secure environment for information sharing. This system will allow a broader set of user communities to benefit from peer-to-peer information sharing.

The last decade has witnessed a rapid proliferation of superscalar cache-based microprocessors to build high-end capability and capacity computers primarily because of their generality, scalability, and cost effectiveness. However, the recent development of massively parallel vector systems is having a significant effect on the supercomputing landscape. In this paper, we compare the performance of the recently-released Cray X1 vector system with that of the cacheless NEC SX-6 vector machine, and the superscalar cache-based IBM Power3 and Power4 architectures for scientific applications. Overall results demonstrate that the X1 is quite promising, but performance improvements are expected as the hardware, systems software, and numerical libraries mature. Code reengineering to effectively utilize the complex architecture may also lead to significant efficiency enhancements.

Operations Funding for the Materials Research Collaborative Access Team. In the proposal they presented five specific objectives for the MR-CAT Insertion Device beam line: (1) enable the accomplishment of the best possible science at MR-CAT; (2) facilitate efficient set-up and operations of a variety of complex materials-related experiments; (3) open the beamlines' facilities to scientists and science projects from non-traditional backgrounds and disciplines, respectively; (4) enable efficient 24 hour use of the beamline through interdisciplinary research teams and appropriate operations support; and (5) develop selected operations modes in support of the MR-CAT institutions, DOE collaborators, and general users.