610 research outputs found
Compressive Privacy for a Linear Dynamical System
We consider a linear dynamical system in which the state vector consists of
both public and private states. One or more sensors make measurements of the
state vector and sends information to a fusion center, which performs the final
state estimation. To achieve an optimal tradeoff between the utility of
estimating the public states and protection of the private states, the
measurements at each time step are linearly compressed into a lower dimensional
space. Under the centralized setting where all measurements are collected by a
single sensor, we propose an optimization problem and an algorithm to find the
best compression matrix. Under the decentralized setting where measurements are
made separately at multiple sensors, each sensor optimizes its own local
compression matrix. We propose methods to separate the overall optimization
problem into multiple sub-problems that can be solved locally at each sensor.
We consider the cases where there is no message exchange between the sensors;
and where each sensor takes turns to transmit messages to the other sensors.
Simulations and empirical experiments demonstrate the efficiency of our
proposed approach in allowing the fusion center to estimate the public states
with good accuracy while preventing it from estimating the private states
accurately
Differentially Private Mixture of Generative Neural Networks
Generative models are used in a wide range of applications building on large
amounts of contextually rich information. Due to possible privacy violations of
the individuals whose data is used to train these models, however, publishing
or sharing generative models is not always viable. In this paper, we present a
novel technique for privately releasing generative models and entire
high-dimensional datasets produced by these models. We model the generator
distribution of the training data with a mixture of generative neural
networks. These are trained together and collectively learn the generator
distribution of a dataset. Data is divided into clusters, using a novel
differentially private kernel -means, then each cluster is given to separate
generative neural networks, such as Restricted Boltzmann Machines or
Variational Autoencoders, which are trained only on their own cluster using
differentially private gradient descent. We evaluate our approach using the
MNIST dataset, as well as call detail records and transit datasets, showing
that it produces realistic synthetic samples, which can also be used to
accurately compute arbitrary number of counting queries.Comment: A shorter version of this paper appeared at the 17th IEEE
International Conference on Data Mining (ICDM 2017). This is the full
version, published in IEEE Transactions on Knowledge and Data Engineering
(TKDE
MM: A general method to perform various data analysis tasks from a differentially private sketch
Differential privacy is the standard privacy definition for performing
analyses over sensitive data. Yet, its privacy budget bounds the number of
tasks an analyst can perform with reasonable accuracy, which makes it
challenging to deploy in practice. This can be alleviated by private sketching,
where the dataset is compressed into a single noisy sketch vector which can be
shared with the analysts and used to perform arbitrarily many analyses.
However, the algorithms to perform specific tasks from sketches must be
developed on a case-by-case basis, which is a major impediment to their use. In
this paper, we introduce the generic moment-to-moment (MM) method to
perform a wide range of data exploration tasks from a single private sketch.
Among other things, this method can be used to estimate empirical moments of
attributes, the covariance matrix, counting queries (including histograms), and
regression models. Our method treats the sketching mechanism as a black-box
operation, and can thus be applied to a wide variety of sketches from the
literature, widening their ranges of applications without further engineering
or privacy loss, and removing some of the technical barriers to the wider
adoption of sketches for data exploration under differential privacy. We
validate our method with data exploration tasks on artificial and real-world
data, and show that it can be used to reliably estimate statistics and train
classification models from private sketches.Comment: Published at the 18th International Workshop on Security and Trust
Management (STM 2022
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