We present a parallel GPU-accelerated algorithm for computing the directed Hausdorff distance from one NURBS surface to another, within a bound. We make use of axis-aligned bounding-box hierarchies that bound the NURBS surfaces to accelerate the computations. We dynamically construct as well as traverse the bounding-box hierarchies for the NURBS surfaces using operations that are optimized for ...

Authentication protocols, run between a so-called prover and a so-called verifier, enable the verifier to decide whether a prover is legitimate or not. Such protocols enable access control, and are used in e.g. logistics, public transport, or personal identification. An authentication protocol is considered secure if an adversary cannot impersonate a legitimate prover. Such an adversary may eav...

In this paper, we classify the RFID distance bounding protocols having bitwise fast phases and no final signature. We also give the theoretical security bounds for two specific classes, leaving the security bounds for the general case as an open problem. As for the classification, we introduce the notion of k-previous challenge dependent (k-PCD) protocols where each response bit depends on the ...

We present new distance computation algorithms using hierarchies of rectangular swept spheres. Each bounding volume of the tree is described as the Minkowski sum of a rectangle and a sphere, and fits tightly to the underlying geometry. We present accurate and efficient algorithms to build the hierarchies and perform distance queries between the bounding volumes. We also present traversal techni...

A number of security systems, from Chip-and-PIN payment cards to contactless subway and train tokens, as well as secure localization systems, are vulnerable to relay attacks. Encrypting the communication between the honest endpoints does not protect against such attacks. The main solution that has been o ered to date is distance bounding, in which a tightly timed exchange of challenges and resp...

Recently, femtocell solutions have been attracting increasing attention since coverage for broadband radios can effectively eliminate wireless notspots. To restrict malicious subscribers from accessing femtocells, 3G/WiMAX standards introduce an access control strategy, called Closed Subscriber Group (CSG). However, CSG only prevents malicious clients, but not rouge femtocells. In 2009, Han et ...

Many security protocols rely on the assumptions 1 on the physical properties in which its protocol sessions will be 2 carried out. For instance, Distance Bounding Protocols take into 3 account the round trip time of messages and the transmission 4 velocity to infer an upper bound of the distance between two 5 agents. We classify such security protocols as Cyber-Physical. 6 The key elements of s...