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Abans de 2015, el títol era Global Citizenship ReportDescripció feta a partir de: 2019, el 25 març 2021

When private set intersection meets big data : an efficient and scalable protocol

Large scale data processing brings new challenges to the design of privacy-preserving protocols: how to meet the increasing requirements of speed and throughput of modern applications, and how to scale up smoothly when data being protected is big. Efficiency and scalability become critical criteria for privacy preserving protocols in the age of Big Data. In this paper, we present a new Private Set Intersection (PSI) protocol that is extremely efficient and highly scalable compared with existing protocols. The protocol is based on a novel approach that we call oblivious Bloom intersection. It has linear complexity and relies mostly on efficient symmetric key operations. It has high scalability due to the fact that most operations can be parallelized easily. The protocol has two versions: a basic protocol and an enhanced protocol, the security of the two variants is analyzed and proved in the semi-honest model and the malicious model respectively. A prototype of the basic protocol has been built. We report the result of performance evaluation and compare it against the two previously fastest PSI protocols. Our protocol is orders of magnitude faster than these two protocols. To compute the intersection of two million-element sets, our protocol needs only 41 seconds (80-bit security) and 339 seconds (256-bit security) on moderate hardware in parallel mode

MST construction in O

We consider a simple model for overlay networks, where all n processes are connected to all other processes, and each message contains at most O(log n) bits. For this model, we present a distributed algorithm that constructs a minimumweight spanning tree in O(log log n) communication rounds, where in each round any process can send a message to each other process. This result is the first to break the Ω(log n) parallel time complexity barrier with small message sizes. Categories and Subject Descriptors F.2 [theory of computation]: analysis of algorithms and problem complexity; G.2.2 [mathematics of computing]: discrete mathematics—graph theor

Energy Efficient Security Framework for Wireless Local Area Networks

Wireless networks are susceptible to network attacks due to their inherentvulnerabilities. The radio signal used in wireless transmission canarbitrarily propagate through walls and windows; thus a wireless networkperimeter is not exactly known. This leads them to be more vulnerable toattacks such as eavesdropping, message interception and modifications comparedto wired-line networks. Security services have been used as countermeasures toprevent such attacks, but they are used at the expense of resources that arescarce especially, where wireless devices have a very limited power budget.Hence, there is a need to provide security services that are energy efficient.In this dissertation, we propose an energy efficient security framework. Theframework aims at providing security services that take into account energyconsumption. We suggest three approaches to reduce the energy consumption ofsecurity protocols: replacement of standard security protocol primitives thatconsume high energy while maintaining the same security level, modification ofstandard security protocols appropriately, and a totally new design ofsecurity protocol where energy efficiency is the main focus. From ourobservation and study, we hypothesize that a higher level of energy savings isachievable if security services are provided in an adjustable manner. Wepropose an example tunable security or TuneSec system, which allows areasonably fine-grained security tuning to provide security services at thewireless link level in an adjustable manner.We apply the framework to several standard security protocols in wirelesslocal area networks and also evaluate their energy consumption performance.The first and second methods show improvements of up to 70% and 57% inenergy consumption compared to plain standard security protocols,respectively. The standard protocols can only offer fixed-level securityservices, and the methods applied do not change the security level. The thirdmethod shows further improvement compared to fixed-level security by reducing(about 6% to 40%) the energy consumed. This amount of energy saving can bevaried depending on the configuration and security requirements

Global predicate analysis and its application to register allocation

Abstract To fully utilize the wide machine resources in modern high-performance microprocessors it is necessary to exploit parallelism beyond individual basic blocks. Architectural support for predicated execution increases the degree of instruction level parallelism by allowing instructions from dtgerent basic blocks to be converted to straight-line code guarded by boolean predicates. However; predicated execution also presents signijcant challenges to an optimizing compiler For example, in live range analysis, a predicated definition does not necessarily end the live range of a virtual register This paper describes techniques to analyze the relations among predicates in order to improve the precision and effectiveness of various compiler analysis and transformation phases in the presence of predicated code. Our predicate analysis operates globally to obtain relations among predicates. Moreover we analyze control flow and predication in a single unifiedframework. The result can be queried by subsequent optimization and analysis phases. Based on this framework, we extend a traditional method to a predicate-aware register allocator which takes global predicate relations into account. We have implemented the proposed algorithms to effectively reduce register pressure. Our experimental results show 24.6% of a large test suite obtain, on average, 20.71% better register allocation due to the algorithms presented in this paper

Progress in Developing Industry Standard Test Requirements for Pb-Free Solder Alloys

Abstract Recently, the industry has seen the development of a wide range of new Pb-free alloys. A significant element of uncertainty within the industry regarding these new alloys is the lack of defined data requirements for alloy acceptance. This paper describes the progress of recent efforts to standardize Pb-free solder alloy testing requirements. Hewlett-Packard, the iNEMI consortium, the Solder Products Value Council, and the IPC are working together to create such standards. To facilitate the standardization of alloy testing, the required tests are divided into three major areas, each of which may be covered by a separate standard. • Material properties • Solder joint reliability • Impact to manufacturing processes This paper presents the status of standardization efforts in each of these three areas