393,116 research outputs found
Quantifying pervasive authentication: the case of the Hancke-Kuhn protocol
As mobile devices pervade physical space, the familiar authentication
patterns are becoming insufficient: besides entity authentication, many
applications require, e.g., location authentication. Many interesting protocols
have been proposed and implemented to provide such strengthened forms of
authentication, but there are very few proofs that such protocols satisfy the
required security properties. The logical formalisms, devised for reasoning
about security protocols on standard computer networks, turn out to be
difficult to adapt for reasoning about hybrid protocols, used in pervasive and
heterogenous networks.
We refine the Dolev-Yao-style algebraic method for protocol analysis by a
probabilistic model of guessing, needed to analyze protocols that mix weak
cryptography with physical properties of nonstandard communication channels.
Applying this model, we provide a precise security proof for a proximity
authentication protocol, due to Hancke and Kuhn, that uses a subtle form of
probabilistic reasoning to achieve its goals.Comment: 31 pages, 2 figures; short version of this paper appeared in the
Proceedings of MFPS 201
Transparency by Design: Closing the Gap Between Performance and Interpretability in Visual Reasoning
Visual question answering requires high-order reasoning about an image, which
is a fundamental capability needed by machine systems to follow complex
directives. Recently, modular networks have been shown to be an effective
framework for performing visual reasoning tasks. While modular networks were
initially designed with a degree of model transparency, their performance on
complex visual reasoning benchmarks was lacking. Current state-of-the-art
approaches do not provide an effective mechanism for understanding the
reasoning process. In this paper, we close the performance gap between
interpretable models and state-of-the-art visual reasoning methods. We propose
a set of visual-reasoning primitives which, when composed, manifest as a model
capable of performing complex reasoning tasks in an explicitly-interpretable
manner. The fidelity and interpretability of the primitives' outputs enable an
unparalleled ability to diagnose the strengths and weaknesses of the resulting
model. Critically, we show that these primitives are highly performant,
achieving state-of-the-art accuracy of 99.1% on the CLEVR dataset. We also show
that our model is able to effectively learn generalized representations when
provided a small amount of data containing novel object attributes. Using the
CoGenT generalization task, we show more than a 20 percentage point improvement
over the current state of the art.Comment: CVPR 2018 pre-prin
A Generic Framework for Reasoning about Dynamic Networks of Infinite-State Processes
We propose a framework for reasoning about unbounded dynamic networks of
infinite-state processes. We propose Constrained Petri Nets (CPN) as generic
models for these networks. They can be seen as Petri nets where tokens
(representing occurrences of processes) are colored by values over some
potentially infinite data domain such as integers, reals, etc. Furthermore, we
define a logic, called CML (colored markings logic), for the description of CPN
configurations. CML is a first-order logic over tokens allowing to reason about
their locations and their colors. Both CPNs and CML are parametrized by a color
logic allowing to express constraints on the colors (data) associated with
tokens. We investigate the decidability of the satisfiability problem of CML
and its applications in the verification of CPNs. We identify a fragment of CML
for which the satisfiability problem is decidable (whenever it is the case for
the underlying color logic), and which is closed under the computations of post
and pre images for CPNs. These results can be used for several kinds of
analysis such as invariance checking, pre-post condition reasoning, and bounded
reachability analysis.Comment: 29 pages, 5 tables, 1 figure, extended version of the paper published
in the the Proceedings of TACAS 2007, LNCS 442
Temporal Relational Reasoning in Videos
Temporal relational reasoning, the ability to link meaningful transformations
of objects or entities over time, is a fundamental property of intelligent
species. In this paper, we introduce an effective and interpretable network
module, the Temporal Relation Network (TRN), designed to learn and reason about
temporal dependencies between video frames at multiple time scales. We evaluate
TRN-equipped networks on activity recognition tasks using three recent video
datasets - Something-Something, Jester, and Charades - which fundamentally
depend on temporal relational reasoning. Our results demonstrate that the
proposed TRN gives convolutional neural networks a remarkable capacity to
discover temporal relations in videos. Through only sparsely sampled video
frames, TRN-equipped networks can accurately predict human-object interactions
in the Something-Something dataset and identify various human gestures on the
Jester dataset with very competitive performance. TRN-equipped networks also
outperform two-stream networks and 3D convolution networks in recognizing daily
activities in the Charades dataset. Further analyses show that the models learn
intuitive and interpretable visual common sense knowledge in videos.Comment: camera-ready version for ECCV'1
Recurrent Relational Networks
This paper is concerned with learning to solve tasks that require a chain of
interdependent steps of relational inference, like answering complex questions
about the relationships between objects, or solving puzzles where the smaller
elements of a solution mutually constrain each other. We introduce the
recurrent relational network, a general purpose module that operates on a graph
representation of objects. As a generalization of Santoro et al. [2017]'s
relational network, it can augment any neural network model with the capacity
to do many-step relational reasoning. We achieve state of the art results on
the bAbI textual question-answering dataset with the recurrent relational
network, consistently solving 20/20 tasks. As bAbI is not particularly
challenging from a relational reasoning point of view, we introduce
Pretty-CLEVR, a new diagnostic dataset for relational reasoning. In the
Pretty-CLEVR set-up, we can vary the question to control for the number of
relational reasoning steps that are required to obtain the answer. Using
Pretty-CLEVR, we probe the limitations of multi-layer perceptrons, relational
and recurrent relational networks. Finally, we show how recurrent relational
networks can learn to solve Sudoku puzzles from supervised training data, a
challenging task requiring upwards of 64 steps of relational reasoning. We
achieve state-of-the-art results amongst comparable methods by solving 96.6% of
the hardest Sudoku puzzles.Comment: Accepted at NIPS 201
- …