Distance-bounding protocols form a family of challenge–response authentication protocols that have been introduced to thwart relay attacks. They enable a verifier to authenticate and to establish an upper bound on the physical distance to an untrusted prover. We provide a detailed security analysis of a family of such protocols. More precisely, we show that the secret key shared between the ver...

In structured prediction, a predictor optimizes an objective function over a combinatorial search space, such as the set of all image segmentations, or the set of all part-of-speech taggings. Unfortunately, finding the optimal structured labeling—sometimes referred to as maximum a posteriori (MAP) inference—is, in general, NP-hard [12], due to the combinatorial structure of the problem. Many in...

Clustering is one of the important aspect in data mining. Clustering means similar group of objects. VA-file is a technique to combat the curse of dimensionality and hence necessarily ignores dependencies across dimensions. Existing methods to prune irrelevant clusters are based on bounding hyper spheres or bounding rectangles, whose lack of tightness compromises their efficiency in exact neare...

We consider the problem of distance bounding verification (DBV), where a proving party claims a distance and a verifying party ensures that the prover is within the claimed distance. Current approaches to “secure” distance estimation use signal’s time of flight, which requires the verifier to have an accurate clock. We study secure DBV using physical channel properties as an alternative to time...

Most previous bounding-box-based segmentation methods assume the bounding box tightly covers the object of interest. However it is common that a rectangle input could be too large or too small. In this paper, we propose a novel segmentation approach that uses a rectangle as a soft constraint by transforming it into an Euclidean distance map. A convolutional encoder-decoder network is trained en...

This paper presents a novel approach is described for realtime human/vehicle classification and motion analysis in real visual surveillance scene. Spatio-temporal 1-D signals based on the distances between the outer contour of binarized silhouette of a motion object and a bounding box placed around the silhouette are chosen as the basic image features called the distance vectors. The spatio-tem...

We present a set of simple techniques for key establishment over a radio link in peer-to-peer networks. Our approach is based on the Diffie-Hellman key agreement protocol, which is known to be vulnerable to the “man-in-the-middle” attack if the two users involved in the protocol do not share any authenticated information about each other (e.g., public keys, certificates, passwords, shared keys,...

We consider the problem of bounding the distance distribution for unrestricted block codes with known distance and/or dual distance. Applying the polynomial method, we provide a general framework for previously known results. We derive several upper and lower bounds both for finite length and for sequences of codes of growing length. Asymptotic results in the paper improve previously known esti...

Relay attacks pose a significant threat against communicating devices that are required to operate within a short-distance from each other and a restricted time frame. In the field of smart cards, distance bounding protocols have been proposed as an effective countermeasure, whereas, in the field of smartphones, many proposals suggest the use of (natural) ambient sensing as an effective alterna...