467068
Run-Time Support for Adaptive Heavyweight Services
By definition, a heavyweight network service requires a significant amount of computation to complete its task. Providing a heavyweight service is challenging for a number of reasons. First, since the service can typically not be provided in a timely fashion using a single server at the remote site, multiple hosts at both the server and client sites must be employed. Second, the available compute and network resources change with respect to time. Thus, an effective service must be adaptive in the sense that it is able to transparently aggregate the available resources and react to the changing availability of these resources. In this paper we present a framework that allows us to build these kinds of adaptive heavyweight services. Experimental results with a distributed visualization service suggest that the cost imposed by the new capability is reasonable.
7567479
Stardust: tracking activity in a distributed storage system
Performance monitoring in most distributed systems provides minimal guidance for tuning, problem diagnosis, and decision making. Stardust is a monitoring infrastructure that replaces traditional performance counters with end-to-end traces of requests and allows for efficient querying of performance metrics. Such traces better inform key administrative performance challenges by enabling, for example, extraction of per-workload, per-resource demand information and per-workload latency graphs. This paper reports on our experience building and using end-to-end tracing as an on-line monitoring tool in a distributed storage system. Using diverse system workloads and scenarios, we show that such fine-grained tracing can be made efficient (less than 6% overhead) and is useful for on- and off-line analysis of system behavior. These experiences make a case for having other systems incorporate such an instrumentation framework.
1480760
Evaluation of a resource selection mechanism for complex network services
Providing complex (resource-intensive) network services is challenging because the resources they need and the resources that are available can vary significantly from request to request. To address this issue, we have proposed a flexible mechanism, called active frames, that provides a basis for selecting a set of available distributed computing resources, and then mapping tasks onto those resources. As a proof of concept, we have used active frames to build a remote visualization service, called Dv, that allows users to visualize the contents of scientific datasets stored at remote locations. We evaluate the performance of active frames, in the context of Dv. In particular, we address the following two questions: (1) what performance penalty do we pay for the flexibility of the active frames mechanism? (2) can the throughput of a service based on active frames be predicted with reasonable accuracy from micro-benchmarks? The results of the evaluation suggest that the overhead imposed by active frames is reasonable (roughly 5%), and that simple models based on micro-benchmarks can conservatively predict measured throughput with reasonable accuracy (at most 20%).
1101949
Preliminary Report on the Design of a Framework for Distributed Visualization
The paper is a preliminary report on the de- sign of a framework, called Dv, for building interactive distributed visualizations on computational grids. The framework is based on a form of mobile object, called an active frame, that consists of application data and a pro- gram that manipulates the data. The system provides a flexible framework for building distributed applications that are performance-portable in the presence of hetero- geneous resources and that adapt to dynamic changes in the status of system resources such as processor cycles and network bandwidth.
3098775
A First Approach to Provide Anonymity in Attribute Certificates
This paper focus on two security services for internet ap- plications: authorization and anonymity. Traditional authorization solu- tions are not very helpful for many of the Internet applications; however, attribute certificates proposed by ITU-T seems to be well suited and provide adequate solution. On the other hand, special attention is paid to the fact that many of the operations and transactions that are part of Internet applications can be easily recorded and collected. Consequently, anonymity has become a desirable feature to be added in many cases. In this work we propose a solution to enhance the X.509 attribute certifi- cate in such a way that it becomes a conditionally anonymous attribute certificate. Moreover, we present a protocol to obtain such certificates in a way that respects users' anonymity by using a fair blind signature scheme. We also show how to use such certificates and describe a few cases where problems could arise, identifying some open problems.
952782
Verification of Authentication Protocols using SDL-method
Authentication between protocol agents is widely studied in the cryptographic protocol analysis area. It is essential in a virtual environment to rely on protocol parties' identity. In the academic literature there are many protocols that provide the authentication property. We present in this paper a new mechanism to verify authentication using SDL, general purpose specification language. We have defined a generic schema in SDL that allow us to specify a security system and check system behavior when a malicious agent ( the intruder ) is present. We have used the EKE authentication protocol to illustrate who the mechanism works.
3830604
A Synchronous Multi-Party Contract Signing Protocol Improving Lower Bound of Steps
Contract signing is a fundamental service in doing business. The Internet has facilitated the electronic commerce, and it is necessary to find appropriate mechanisms for contract signing in the digital world. A number of two-party contract signing protocols have been proposed with various features. Nevertheless, in some applications, a contract may need to be signed by multiple parties. Less research has been done on multi-party contract signing. In this paper, we propose a new synchronous multi-party contract signing protocol that, with n parties, it reaches a lower bound of 3(n − 1) steps in the all-honest case and 4n − 2 steps in the worst case (i.e., all parties contact the trusted third party). This is so far the most efficient synchronous multi-party contract signing protocol in terms of the number of messages required. We further consider the additional features like timeliness and abuse-freeness in the improved version.