8388633
Integration of quantum cryptography in 802.11 networks
Quantum cryptography is considered as a promising solution towards absolute security in long-term cryptosystems. While the application of quantum cryptography in fiber networks has significant advances, research on the application of quantum cryptography in mobile networks is still premature. In this paper, we analyze the interests of using quantum technique for the distribution of encryption keys in 802.11 wireless networks. We also propose a scheme for the integration of quantum cryptography in 802.11i security mechanisms for the establishment of the PTK (pairwise transient key).
14628738
Analysis of Protocol Operations and Scalability of COPS-SLS Negotiation System
Dynamic service level negotiation is necessary to flexibly allocate resources according to QoS demands of a host or a domain. We have designed COPS-SLS as a service level negotiation protocol for IP-based networks. In this paper, we analyse a COPS-SLS-based negotiation system from the protocol design and system’s scalability perspectives. This analysis is useful not only to the improvement of the COPS-SLS protocol design but also to the deployment of a service level negotiation system in general.
18230962
Efficient and effective array bound checking
Array bound checking refers to determining whether all array references in a program are within their declared ranges. This checking is critical for software verification and validation because subscripting arrays beyond their declared sizes may produce unexpected results, security holes, or failures. It is available in most commercial compilers but current implementations are not as efficient and effective as one may have hoped: (1) the execution times of array bound checked programs are increased by a factor of up to 5, (2) the compilation times are increased, which is detrimental to development and debugging, (3) the related error messages do not usually carry information to locate the faulty references, and (4) the consistency between actual array sizes and formal array declarations is not often checked.This article presents two optimization techniques that deal with Points 1, 2, and 3, and a new algorithm to tackle Point 4, which is not addressed by the current literature. The first optimization technique is based on the elimination of redundant tests, to provide very accurate information about faulty references during development and testing phases. The second one is based on the insertion of unavoidable tests to provide the smallest possible slowdown during the production phase. The new algorithm ensures the absence of bound violations in every array access in the called procedure with respect to the array declarations in the calling procedure. Our experiments suggest that the optimization of array bound checking depends on several factors, not only the percentage of removed checks, usually considered as the best improvement measuring metrics. The debugging capability and compile-time and run-time performances of our techniques are better than current implementations. The execution times of SPEC95 CFP benchmarks with range checking added by PIPS, our Fortran research compiler, are slightly longer, less than 20%, than that of unchecked programs. More problems due to functional and data recursion would have to be solved to extend these results from Fortran to other languages such as C, C++, or Java, but the issues addressed in this article are nevertheless relevant.
14226937
Self-Learning IP Traffic Classification Based on Statistical Flow Characteristics
A number of key areas in IP network engineering, management and surveillance greatly benefit from the ability to dynamically identify traffic flows according to the applications responsible for their creation. Currently such classifications rely on selected packet header fields (e.g. destination port) or application layer protocol decoding. These methods have a number of shortfalls e.g. many applications can use unpredictable port numbers and protocol decoding requires high resource usage or is simply infeasible in case protocols are unknown or encrypted. We propose a framework for application classification using an unsupervised machine learning (ML) technique. Flows are automatically classified based on their statistical characteristics. We also propose a systematic approach to identify an optimal set of flow attributes to use and evaluate the effectiveness of our approach using captured traffic traces.
6207354
Development of Some Methods and Tools for Discovering Conceptual Knowledge
This abstract summarizes key points of our ongoing project that aims at developing several new methods in knowledge discovery in databases (KDD) and implementing them together with related techniques in an interactive-graphic environment. This research lies in several areas if KDD such as supervised classi fication, conceptual clustering, discovery of association rules, parallel and distributed data mining, genetic programming. Some of them are the continuation of our work done so far [1], [2], [3], and some others have been started recently
18341353
Alias verification for Fortran code optimization
Abstract Alias analysis for Fortran is less complicated than for programming languages with pointers but many real Fortran programs violate the standard: a formal parameter or a common variable that is aliased with another formal parameter is modified. Compilers, assuming standard-conforming programs, consider that an assignment to one variable will not change the value of any other variable, allowing optimizations involving the aliased variables. Higher performance results but anything may happen: the program may appear to run normally, or may produce incorrect answers, or may behave unpredictably. The results may depend on the compiler and the optimization level. To guarantee the standard conformance of programs and to maintain the referential transparency in order to make program analyses exact and program optimizations safe, precise alias information retrieval at a reasonable cost, especially the determination of overlaps between arrays are studied in this paper. Static analyses and code instrumentation are used to find all violations of the prohibitions against aliasing in Fortran code. Alias violation tests are inserted only at places where it cannot be proved statically that they are useless in order to reduce the number of dynamic checks at run-time. A specific memory location naming technique is used to compact representation and enhance the precision of alias analysis. Modifications on the dependence graph created by aliasing are also studied to show the impact of aliases on some program optimizing transformations. Experimental results on SPEC95 benchmark are presented and some related issues are also discussed.
7004938
Flexible and Manageable Delegation of Authority in RBAC
One of the most challenging problems in managing large networks is the complexity of security administration. Role based access control (RBAC) has become the predominant model for advanced access control. Flexibility and manageability are important requirements for any delegation system which is one of the most important access control management mechanisms in authorisation systems. This paper proposes a delegation model that satisfies these requirements.