31352363
Some Computational Problems of Cryptographic Significance Concerning Elliptic Curves over Rings
Elliptic curves over the ring Zn were first employed by Lenstra [Len1, Len2] to present his algorithm on factorization of integers. These curves have also been used to construct new public-key cryptographic schemes [Dem, Koy, KMOV, Men]. Elliptic analogs of the RSA-scheme have been proposed in [Dem, Koy, KMOV], and an elliptic analog of Rabin-type scheme has been proposed in [KMOV]. In this paper we consider the following computational problems of cryptographic significance concerning elliptic curves over the ring Zn with n being square-free: (1) Given an odd positive integer n, and integers a, b such that 4a+27b is prime to n, to compute the number of rational points on the elliptic curve E defined by Y=X +aX+b over Zn . (2) Given an odd positive integer n, integers a, b with 4a+27b prime to n, and a point P=(u, v) on the elliptic curve E defined by Y=X+aX+b over Zn , where u, v # Zn , to find a rational point Q on E such that 2Q=P.
40799553
Function Field Sieve Method for Discrete Logarithms over Finite Fields
We present a function field sieve method for discrete logarithms over finite fields. This method is an analog of the number field sieve method originally developed for factoring integers. It is asymptotically faster than the previously known algorithms when applied to finite fields Fpn, where p6?n.
29173670
Dynamic Visualization of Spatially Referenced Information
This paper proposes a dynamic visualization approach that combines the graph metaphor and the spatial metaphor for visualizing and navigating spatially referenced data. It provides users with a “marching” scheme for viewing a series of graphs G1, G2, ... Gn that are related to a spatial map. Moreover, It provides three types of navigation mechanisms. This dynamic visualization can facilitate the processes of spatially referenced data mining.
7442937
SEED: Scalable, efficient enforcement of dependences
Instruction issue logic is a critical component in modern high-performance out-of-order processors. The ever increasing latencies found in modern processors, mostly associated with memory accesses and longer pipelines, can be attenuated using large issue queues. Conventional designs rely on atomic wakeup-select cycles to ensure compact scheduling. These designs must aggressively utilize broadcasting, compaction, and heavily-ported structures that scale poorly in terms of both power consumption and access time. To provide high scheduling flexibility and large instruction capacity without incurring prohibitive latency and energy overhead, we propose a novel scheme that uses an out-of-order, broadcast-free instruction wakeup block feeding an in-order scheduler. Multi-banked, index-based structures are used throughout this scheme to provide a high degree of scalability while achieving efficient dependence tracking, resulting in good overall performance and energy efficiency. We call this design "Scalable, Efficient Enforcement of Dependences (SEED)". We present a detailed design and analysis of SEED through an extensive evaluation. Compared to a conventional issue queue design, which is assumed favorably to scale in size without any impact on cycle time, the performance degradation of our design is 3% for both INT and FP suites of SPEC CPU2000. For such a small performance cost, SEED enjoys a 19% reduction in total chip power consumption for a 32-entry configuration. We also synthesize SEED and a conventional issue logic with 90nm standard cell logic. Synthesis results show that SEED can cycle twice the speed of a conventional issue logic of equivalent size. Cycling at the same frequency, SEED consumes ten times less dynamic power and five times less static power while achieving substantial area savings.
11321138
Attributed graph visualization of collaborative workspaces
Collaborative workspaces are becoming increasingly commonplace, particularly in large, distributed organizations where virtual teams formed in order to jointly carry out collaborative project work. Typical collaborative workspaces often have a large number of objects and relations as well as their associated domain-specific attributes. The visualization of these domain-specific attributes is the challenge of this research. This paper presents a new approach for visualizing the attributes of objects and relations in collaborative workspaces. This new visualization provides not only a structural view of the collaborative workspaces but also a graphical view of a variety of domain-specific attributes associated with collaborative objects and relations. This paper also describes a framework for the attributed visualization of collaborative workspaces.
12101937
Hierarchical information visualization using enccon model
This paper describes a new efficient approach for visualizing large hierarchical information. Our technique is based on the connection + enclosure visualization model [1] from which the area division is used for the recursive positioning of nodes, while a node-link diagram is still drawn to present the entire hierarchical structure. We inherit the advantages of Space-Optimized (SO) Tree technique [1] that can enhance the usability of display space by using area division. However, we replace a set of polygons used in SO Tree by a set of rectangles for the area division. This not only decreases the computation cost in calculating geometrical polygons, but also greatly reduces the human perceptual and cognitive loads spent on understanding the underlying hierarchical structure. We use semantic zooming technique to enlarge a particular viewing area and filter out the rest of structure that is less interested. The navigation is accommodated by animation in order to preserve the mental map [2].
2042207
Hybrid Authentication and Key Management Scheme for WSANs
Wireless Sensor and Actor Networks (WSANs) consist of three types of nodes with different capabilities and functions. Because of these heterogeneities, current network security mechanisms would be hard to satisfy the security/cost requirements of all types of nodes. In this paper, we propose an integrated security approach, called Hybrid Security Scheme (HSS). It splits a WSAN into two layers, the sink-actor layer and the actor-sensor layer, according to nodes’ functionalities and capacities. Different security mechanisms are provided to achieve the security services at corresponding levels. Furthermore, an adaptive switching mechanism is provided to satisfy the dynamic topology of network, and several methods are also used to reduce the system costs.