## Universally Optimal Distributed Algorithms for Known Topologies

Many distributed optimization algorithms achieve existentially-optimal running times . Still, most networks of interest allow forexponentially faster algorithms . We resolve these 25-year-old open problems in the known-topology setting . We provide several (equivalent) graph parameters and show theyare tight universal lower bounds for the above problems .…

## Linear and Sublinear Time Spectral Density Estimation

We analyze the popular kernel polynomial method (KPM) for approximating the spectral density (eigenvalue distribution) of a symmetric (or Hermitian) matrix . We prove that a simple and practicalvariant of the KPM algorithm can approximate the accuracy in the Wasserstein-1 distance with roughly $O(n/\text{poly}(\epsilon)$ matrix-vector multiplications with $A$ This yields a provable linear timeresult for the problem .…

## Determinisability of register and timed automata

We draw the complete decidability/complexitylandscape of the deterministic membership problem, in the setting of both register and timed automata . We prove that the problem is decidable when the input automaton is a one-clocknondeterministic timed automaton without epsilon transitions . We show that in all the other cases the problem in all other cases is undecidable, i.e.…

## Hybrid QSS and Dynamic Extended Term Simulation Based on Holomorphic Embedding

Power system simulations that extend over a time period of minutes, hours, oreven longer are called extended-term simulations . Extended-term simulation is needed for many power system analysis tasks (e.g., resilience analysis, renewable energyintegration, cascading failures) The conventional approaches are insufficient for dealing with the extended-time simulation of multi-timescaleprocesses .…

## Representing Polynomial Splines over Infinite Hierarchical Meshes by Finite Automata

We propose a data structure based on finite automata for representingpolynomial splines over infinite hierarchical meshes . It allows to store andoperate such splines using only finite amount of memory . This naturally extendsa classical framework of hierarchical tensor product B-splines for infinitemeshes in a way suitable for computing .…

## Rethinking the Backdoor Attacks Triggers A Frequency Perspective

Backdoor attacks have been considered a severe security threat to deeplearning . Such attacks can make models perform abnormally on inputs with triggers and still retain state-of-the-art performance on cleandata . Many current backdoor attacks exhibit severe high-frequency artifacts, which persistacross different datasets and resolutions .…

## An Object Detection based Solver for Google s Image reCAPTCHA v2

Previous work showed that reCAPTCHA v2’s image challenges could be solved byautomated programs armed with Deep Neural Network (DNN) image classifiers andvision APIs provided by off-the-shelf image recognition services . We propose afully automated object detection based system with an online success rate of 83.25%, the highestsuccess rate to date, and it takes only 19.93 seconds (including network delays) on average to crack a challenge .…

## Prism Private Verifiable Set Computation over Multi Owner Outsourced Databases

Prism is a secret sharing based approach to compute privateset operations (i.e., intersection and union), as well as aggregates overoutsourced databases belonging to multiple owners . Prism enables data owners topre-load the data onto non-colluding servers and exploits the additive and multiplicative properties of secret-shares to compute the above-listedoperations in (at most) two rounds of communication between the servers and the querier .…

## Evaluating Medical IoT MIoT Device Security using NISTIR 8228 Expectations

How do healthcare organizations evaluate the cybersecurity and privacy protection of Medical Internet ofThings (MIoT) used in clinical settings? This paper suggests an approach for such evaluation using National Institute of Standards and Technology (NIST)guidance) How do organizations (from small Practices to large HDOs) evaluate compliance with NISTIR 8228 Expectations?…

## Decentralized Cross Network Identity Management for Blockchain Interoperation

Interoperation for data sharing between permissioned blockchain networksrelies on networks’ abilities to independently authenticate requests andvalidate proofs accompanying the data . This requires counterparty networks to know the identities andcertification chains of each other’s members . But permissioned networks are ad hoc consortia of existing organizations, whose network affiliations may not be well-known or well-established even though their individual identities are .…

## Towards Optimal Use of Exception Handling Information for Function Detection

Function entry detection is critical for security of binary code . Call frames have been used inexception-handling for function start detection . But existing methods have two problems: combining call frames with heuristic-based approaches often brings error and uncertain benefits .…

## TenSEAL A Library for Encrypted Tensor Operations Using Homomorphic Encryption

TenSEAL is an open-source library for Privacy-Preserving Machine Learning usingHomomorphic Encryption that can be easily integrated within popular machinelearning frameworks . We benchmark our implementation using MNIST and show that an encrypted convolutional neural network can be evaluated in less than asecond, using less than half a megabyte of communication.…

## Shared Dining Broadcasting Secret Shares using Dining Cryptographers Groups

A k-anonymous broadcast can be implemented using a small group of diningcryptographers to first share the message, followed by a flooding phase started by group members . Members have little incentive to forward the message in atimely manner, as forwarding incurs costs, or they may even profit from keeping the message .…