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Herglotz functions inevitably appear in pure mathematics, mathematical physics, and engineering with a wide range of applications. In particular, they are the pertinent functions to model passive systems, and thus appear in modeling of electromagnetic phenomena in circuits, antennas, materials, and scattering. In this chapter, we review the basic theory of Herglotz functions and its applications t
Optical wireless networks realized by means of gigabit optical wireless communication (OWC) systems are becoming, in a variety of applications, an important alternative, or a complementary solution, to their fiber-based counterparts. However, performance of the OWC systems can be considerably degraded in periods of unfavorable weather conditions, such as heavy fog, which temporarily reduce the eff
Connected Autonomous Vehicles (AV)s can transform urban transportation systems and have the potential to improve the safety and efficiency, since human errors and distractions are removed. However, these systems are vulnerable to model uncertainties, communication impairments associated with the wireless communication, and external disturbances. As a result, vehicles need to drive at low speed and
The learning with errors (LWE) problem is one of the main mathematical foundations of post-quantum cryptography. One of the main groups of algorithms for solving LWE is the Blum–Kalai–Wasserman (BKW) algorithm. This paper presents new improvements of BKW-style algorithms for solving LWE instances. We target minimum concrete complexity, and we introduce a new reduction step where we partially reduc
In this paper, we present a side-channel attack on a first-order masked implementation of IND-CCA secure Saber KEM. We show how to recover both the session key and the long-term secret key from 24 traces using a deep neural network created at the profiling stage. The proposed message recovery approach learns a higher-order model directly, without explicitly extracting random masks at each executio
The improvements in GPU hardware, including hardware-accelerated ray tracing, and the push for fully dynamic realistic-looking video games, has been driving more research in the use of ray tracing in real-time applications. The work described in this thesis covers multiple aspects such as optimisations, adapting existing offline methods to real-time constraints, and adding effects which were hard
Digital twins are taking a central role in the industry 4.0 narrative. However, they are still illusive. Many aspects of the digital-twins have yet to materialize. For example, to what degree will they be integrated into cloud and industry 4.0 systems as well as how and if they should augment their physical counterpart. Those choices are accompanied by challenging security aspects, many of which h
G.fast is a gap-bridging broadband technology on the way to a fully optical access network. G.fast is deployed in hybrid fiber-copper access networks and aiming to offer ubiquitous low-cost and high-speed broadband. For network operators, it is crucial to determine the location from where to deploy G.fast, the expected network coverage, and the expected bit rates. In this paper, we perform network
The steadily increasing Internet of Things (IoT) devices are vulnerable to be used as bots to launch distributed-denial-of-service (DDoS) attacks. In this paper, we present X-Pro, a distributed XDP proxy to counteract DDoS attacks. We propose a source-based defense mechanism where proxies located between the IoT devices and the victim performs flow policing on all IoT traffic from a single adminis
Traditional network architecture design of Low Power Wide Area Networks (LPWAN) is incapable of dynamically scaling resources based on the served traffic and requires manual procedures for network capacity upgrades. Today's over-provisioning approach based on proprietary hardware (HW) would not be cost and energy efficient to cope with the ever-increasing scale of Internet of Things (IoT) devices
Cryptosystems based on the learning with errors (LWE) problem are assigned a security level that relates to the cost of generic algorithms for solving the LWE problem. This includes at least the so-called primal and dual lattice attacks. In this paper, we present an improvement of the dual lattice attack using an idea that can be traced back to work by Bleichenbacher. We present an improved distin
Caustics are a challenging light transport phenomenon to render in real-time, and most previous approaches have used screen-space accumulation based on the fast rasterization hardware of GPUs. This limits the position of photon collection points to first hit screen space locations, and leads to missing caustics that should be visible in a mirror’s reflection. In this paper we propose an algorithm
One important open question in side-channel analysis is to find out whether all the leakage samples in an implementation can be exploited by an adversary, as suggested by masking security proofs. For attacks exploiting a divide-and-conquer strategy, the answer is negative: only the leakages corresponding to the first/last rounds of a block cipher can be exploited. Soft Analytical Side-Channel Atta
We define a ray, show how to use ray intervals, and demonstrate how to specify a ray using DirectX Raytracing (DXR).
The traditional quadratic formula is often presented as the way to compute the intersection of a ray with a sphere. While mathematically correct, this factorization can be numerically unstable when using floating-point arithmetic. We give two little-known reformulations and show how each can improve precision.
Unlike rasterization, where one can rely on pixel quad partial derivatives, an alternative approach must be taken for filtered texturing during ray tracing. We describe two methods for computing texture level of detail for ray tracing. The first approach uses ray differentials, which is a general solution that gives high-quality results. It is rather expensive in terms of computations and ray stor
We describe simple methods for how to filter environment maps using ray cones and ray differentials in a ray tracing engine.
In this thesis, we investigate and develop new methods for efficient and functional use of resources in edge networks. Setting this work aside from previous work, we study User Generated Content (UGC) such as social media information and data generated in the new emerging Internet of Things systems. We present efficient solutions for placing such content and managing which network resources should
Internet of Things (IoT) is the next generation of network scenario where billions of devices are connected to the internet and capable to communicate with each other. However, they are especially vulnerable to Denial of Service (DoS) attack, which typically launched by overloading the server with bogus messages. Hence, unnecessary computation is performed by the IoT units, which can seriously wor
This survey overviews the potential use of cryptographic primitives in the fifth-generation mobile communications system (aka 5G) and beyond. It discusses the new security challenges that come with 5G and presents the upcoming security architecture. It shows the use of current cryptographic algorithms and discusses new algorithms or modifications of existing ones, that can be relevant. It also dis
