The Experts below are selected from a list of 1336191 Experts worldwide ranked by ideXlab platform
Srinivas Vivek - One of the best experts on this subject based on the ideXlab platform.
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A Practical Leakage-Resilient Signature Scheme in the Generic Group Model
Selected Areas in Cryptography, 2013Co-Authors: David Galindo, Srinivas VivekAbstract:We propose a leakage-resilient signature scheme in the continual leakage Model that is based on a well-known identity-based encryption scheme by Boneh and Boyen (Eurocrypt 2004). The proposed signature scheme is the most efficient among the existing schemes that allow for continual leakage. Its efficiency is close to that of non leakage-resilient pairing-based signature schemes. It tolerates leakage of almost half of the bits of the secret key at every new signature invocation. We prove the security of the new scheme in the generic bilinear Group Model.
Bei Liang - One of the best experts on this subject based on the ideXlab platform.
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Efficient Leakage-Resilient Signature Schemes in the Generic Bilinear Group Model
Information Security Practice and Experience, 2014Co-Authors: Fei Tang, Qihua Niu, Hongda Li, Bei LiangAbstract:We extend the techniques of Kiltz et al. (in ASIACRYPT 2010) and Galindo et al. (in SAC 2012) to construct two efficient leakage-resilient signature schemes. Our schemes based on Boneh-Lynn-Shacham (BLS) short signature and Waters signature schemes, respectively. Both of them are more efficient than Galindo et al.’s scheme, and can tolerate leakage of (1 − o(1))/2 of the secret key at every signature invocation. The security of the proposed schemes are proved in the generic bilinear Group Model (in our first scheme which is based on the BLS signature, a random oracle is needed for the proof).
David Galindo - One of the best experts on this subject based on the ideXlab platform.
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A Practical Leakage-Resilient Signature Scheme in the Generic Group Model
Selected Areas in Cryptography, 2013Co-Authors: David Galindo, Srinivas VivekAbstract:We propose a leakage-resilient signature scheme in the continual leakage Model that is based on a well-known identity-based encryption scheme by Boneh and Boyen (Eurocrypt 2004). The proposed signature scheme is the most efficient among the existing schemes that allow for continual leakage. Its efficiency is close to that of non leakage-resilient pairing-based signature schemes. It tolerates leakage of almost half of the bits of the secret key at every new signature invocation. We prove the security of the new scheme in the generic bilinear Group Model.
Fei Tang - One of the best experts on this subject based on the ideXlab platform.
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Efficient Leakage-Resilient Signature Schemes in the Generic Bilinear Group Model
Information Security Practice and Experience, 2014Co-Authors: Fei Tang, Qihua Niu, Hongda Li, Bei LiangAbstract:We extend the techniques of Kiltz et al. (in ASIACRYPT 2010) and Galindo et al. (in SAC 2012) to construct two efficient leakage-resilient signature schemes. Our schemes based on Boneh-Lynn-Shacham (BLS) short signature and Waters signature schemes, respectively. Both of them are more efficient than Galindo et al.’s scheme, and can tolerate leakage of (1 − o(1))/2 of the secret key at every signature invocation. The security of the proposed schemes are proved in the generic bilinear Group Model (in our first scheme which is based on the BLS signature, a random oracle is needed for the proof).
George P. Richardson - One of the best experts on this subject based on the ideXlab platform.
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Group Model building scripts as a collaborative planning tool
Systems Research and Behavioral Science, 2012Co-Authors: Peter S. Hovmand, George P. Richardson, David F. Andersen, E A J A Rouwette, Annaliese CalhounAbstract:Group Model building (GMB) is a participatory method for involving stakeholders in the process of developing system dynamics Models. GMB has historically consisted of undocumented structured small-Group exercises. This paper describes an effort to document GMB scripts called Scriptapedia, and how documented GMB scripts can be used to design more effective GMB sessions that address cultural and ideological barriers to collaboration. A case study of a project to develop a coordinated community response to domestic violence is used to illustrate the use of scripts for planning collaboration. The paper concludes with a discussion of potential limitations of scripts and implications for future research. Copyright © 2012 John Wiley & Sons, Ltd.
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Scriptapedia: A Handbook of Scripts for Developing Structured Group Model Building Sessions
2011Co-Authors: Peter S. Hovmand, George P. Richardson, David F. Andersen, Etiënne A. J. A. Rouwette, Annaliese Calhoun, K. Rux, T. HowerAbstract:This paper describes a handbook of scripts—Scriptapedia—for developing structured Group Model building sessions. Andersen and Richardson (1997) have identified the importance of standardized protocols or “scripts” in Group Model building (GMB). GMB scripts have historically existed as undocumented structured small Group exercises. Scriptapedia represents an effort to improve the practice of GMB as well the research into GMB effectiveness. We describe elements of scripts, case applications of Scriptapedia, and discuss uses, misuses, and misunderstandings of scripts. The handbook is included as an appendix to the paper.
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Using a Group Decision Support System to add Value to Group Model Building
System Dynamics Review, 2010Co-Authors: Fran Ackermann, David F. Andersen, Colin Eden, George P. RichardsonAbstract:This note intends to contribute to the practice of Group Model building by presenting Group Model-building scripts that can (1) create a preliminary problem boundary using less than one hour of Group time, (2) convene discussions with the Group that explicitly link dynamic structure with system behaviour, and (3) allow participants to 'zoom' between a micro and a macro view of system structure. These scripts may be used during early phases of problem structuring. They build on an extended program of inquiry dating back to the Stirling System Dynamics Conference of 1994, and they utilize a well-established Group decision support system to facilitate Group discussion, negotiation, and decision.
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Scripts for Group Model building
System Dynamics Review, 1997Co-Authors: David F. Andersen, George P. RichardsonAbstract:Building Models directly with client Groups has become increasingly common in the field of system dynamics. For the past nine years, the Modeling Group at the University at Albany has been experimenting with techniques handling the complex Modeling and facilitation processes involved in Group work. This article extends the previously reported work by discussing specific scripted techniques used to implement the Group Modeling building approach. The authors’ purpose is to initiate a larger discussion of shared scripts and techniques for Group Model building. The discussion is divided into planning for a Group Model building conference, scheduling the day, particular scripts and techniques for various Group Model building tasks, and closing a Group Modeling conference. © 1997 by John Wiley & Sons, Ltd. Syst. Dyn. Rev. 13, 107‐129, 1997 (No. of Figures: 4 No. of Tables: 0 No. of Refs: 40) Model building or Model refinement working directly with a small Group of clients has become increasingly common in the field of system dynamics. Almost ten years ago Jac Vennix (Vennix et al. 1988) described a procedure for involving health care practitioners in the Netherlands in the construction and refinement of a dynamic Model of health care, an approach which he has continued to develop (Vennix 1990; 1996). Barry Richmond (1987; 1997) has described the Strategic Forum as a way to involve clients directly in Model building and analysis. Many consultants have refined the practice of developing causal loop sketches with direct involvement of client Groups to include preliminary Model development, refinement, and presentation. Outside the field of system dynamics, other systems thinkers and Group decision support experts have similarly developed advanced approaches to working with small Groups to support system conceptualization, Model formulation, and decision making. Particularly notable is the work of Colin Eden (Eden et al. 1983; Eden 1989; Eden and Ackermann 1992), John Bryson (Bryson and Finn 1995; Bryson 1995), and John Rohrbaugh (see references below). This article suggests that Modelers who engage in Modeling with Groups rely on fairly sophisticated pieces of small Group process, which we will call ‘‘scripts.’’ A full multi-day Modeling conference consists of a sequence of such scripts placed
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Group Model building: adding more science to the craft
System Dynamics Review, 1997Co-Authors: David F. Andersen, George P. Richardson, Jac A. M. VennixAbstract:This article discusses the issue of making Group Model building interventions more of a science than an art by outlining a number of requirements of a research program. Important elements that are discussed are the various goals of Group Model building interventions and the components and scripts of an intervention. Then the problem of theory development is discussed, together with a number of hypotheses which the authors suggest need more investigation. The article also discusses issues related to the selection of an appropriate research design, as well as a number of thorny measurement problems. © 1997 by John Wiley & Sons, Ltd. Syst. Dyn. Rev. 13, 187‐201, 1997 (No. of Figures: 0 No. of Tables: 0 No. of Refs: 36) The articles in this special issue have presented a number of standard procedures of Group Model-building approaches, as well as results from empirical studies aiming to identify the success of Modeling with client Groups. From these articles it becomes clear that Group Model building is still more art than science. Research on the effects of Group Model building is scarce; it focuses on a wide variety of outcomes and variables, and research designs differ quite considerably. Instead of a solid research program creating replicable 1 and cumulative results, we seem to have series of presumptions and hunches being repeated in a descriptive literature with little empirical evidence, certainly lacking any sense of competing propositions or refutability of the claims being made (most often by the practitioners who are using the system-intervention approach). The norm for research seems to be to posit an intuitively grounded hunch about what will work with a Group and then to design a facilitated conference process around that hunch. If the interventions are successful (in the sense that paying clients like them and are willing to fund them being repeated), then the hunch is substantiated and the best intuitive practice continues. It seems that legends about what is working grow up around these interventions in what can only be described as superstitious behavior. An example may help here. Those of us who work in the field of system dynamics have long held the belief that one of the great benefits of our Modeling craft is that
