24 research outputs found
Convergence analysis of the information matrix in Gaussian belief propagation
Gaussian belief propagation (BP) has been widely used for distributed
estimation in large-scale networks such as the smart grid, communication
networks, and social networks, where local measurements/observations are
scattered over a wide geographical area. However, the convergence of Gaus- sian
BP is still an open issue. In this paper, we consider the convergence of
Gaussian BP, focusing in particular on the convergence of the information
matrix. We show analytically that the exchanged message information matrix
converges for arbitrary positive semidefinite initial value, and its dis- tance
to the unique positive definite limit matrix decreases exponentially fast.Comment: arXiv admin note: substantial text overlap with arXiv:1611.0201
Peer-to-Peer Secure Multi-Party Numerical Computation Facing Malicious Adversaries
We propose an efficient framework for enabling secure multi-party numerical
computations in a Peer-to-Peer network. This problem arises in a range of
applications such as collaborative filtering, distributed computation of trust
and reputation, monitoring and other tasks, where the computing nodes is
expected to preserve the privacy of their inputs while performing a joint
computation of a certain function. Although there is a rich literature in the
field of distributed systems security concerning secure multi-party
computation, in practice it is hard to deploy those methods in very large scale
Peer-to-Peer networks. In this work, we try to bridge the gap between
theoretical algorithms in the security domain, and a practical Peer-to-Peer
deployment.
We consider two security models. The first is the semi-honest model where
peers correctly follow the protocol, but try to reveal private information. We
provide three possible schemes for secure multi-party numerical computation for
this model and identify a single light-weight scheme which outperforms the
others. Using extensive simulation results over real Internet topologies, we
demonstrate that our scheme is scalable to very large networks, with up to
millions of nodes. The second model we consider is the malicious peers model,
where peers can behave arbitrarily, deliberately trying to affect the results
of the computation as well as compromising the privacy of other peers. For this
model we provide a fourth scheme to defend the execution of the computation
against the malicious peers. The proposed scheme has a higher complexity
relative to the semi-honest model. Overall, we provide the Peer-to-Peer network
designer a set of tools to choose from, based on the desired level of security.Comment: Submitted to Peer-to-Peer Networking and Applications Journal (PPNA)
200
From Internal to External: An Integrated Theoretical Framework for Open Innovation
The traditional resource-based view (RBV) accentuates the heterogeneous and imperfect mobile resources serve as key determinants of the competitiveness of organizations. However, social capital theory seems to be advocated leveraging the resources residing in the relationships among individuals to facilitate the organizational performances. The open innovation product, i.e., an Open Source Software (OSS) project, consists of a group of self-organizing individuals who collaboratively co-create an innovation. Much of our understandings of OSS an open innovation is based on studies that focused on the internal resources (i.e., on the co-workers predominantly) leaving little regards to the fact that such an open innovation organization functions in a larger community of projects and people. In this regard, it is imperative to jointly build upon the RBV and social capital theory to take a broader, embracing investigation of an open innovation, i.e. open source software (OSS), system to unveil how internal and external resources can facilitate the innovation legitimacy. In particular, the internal resources include the tangible resources, such as workforce and extent of contribution, and intangible resource like governance structure. The external resources include diverse forms of social capital, such as structural, cognitive, and relational social capital. This ongoing work proposed a theoretical framework to articulate how the interplay between internal and external resources can promote the innovation legitimacy in the OSS context
Peer-to-Peer Secure Multi-Party Numerical Computation
We propose an efficient framework for enabling secure multi-party numerical
computations in a Peer-to-Peer network. This problem arises in a range of
applications such as collaborative filtering, distributed computation of trust
and reputation, monitoring and numerous other tasks, where the computing nodes
would like to preserve the privacy of their inputs while performing a joint
computation of a certain function.
Although there is a rich literature in the field of distributed systems
security concerning secure multi-party computation, in practice it is hard to
deploy those methods in very large scale Peer-to-Peer networks. In this work,
we examine several possible approaches and discuss their feasibility. Among the
possible approaches, we identify a single approach which is both scalable and
theoretically secure.
An additional novel contribution is that we show how to compute the
neighborhood based collaborative filtering, a state-of-the-art collaborative
filtering algorithm, winner of the Netflix progress prize of the year 2007. Our
solution computes this algorithm in a Peer-to-Peer network, using a privacy
preserving computation, without loss of accuracy.
Using extensive large scale simulations on top of real Internet topologies,
we demonstrate the applicability of our approach. As far as we know, we are the
first to implement such a large scale secure multi-party simulation of networks
of millions of nodes and hundreds of millions of edges.Comment: 10 pages, 2 figures, appeared in the 8th IEEE Peer-to-Peer Computing,
Aachen, Germany, Sept. 200
Upscaling in the sharing economy: insights from the UK
Aimed at academics, private businesses, investors and public sector bodies, this report develops a typology of upscaling models in the sharing economy across three key sectors: accommodation, transportation, and professional and personal services