Ludo Tolhuizen

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—Lighting is a major part of energy consumption in buildings. Lighting systems will thus be one of the important component systems of a smart grid for dynamic load management services like demand response. We consider the problem of control of multiple lighting systems in a building for providing demand response service. In the scenario considered in this(More)
Motivated by a recently introduced HIMMO key distribution scheme, we consider a modification of the noisy polynomial interpolation problem of recovering an unknown polynomial f (X) ∈ Z[X] from approximate values of the residues of f (t) mod-ulo a prime p at polynomially many points t taken from a short interval.
We consider the problem of determining the minimum number N<sub>d</sub> of unit disks that is required to block all rays emanating from a point P in the two-dimensional space, where each disk has at least a distance d to point P and to any other disk. We study the asymptotic behavior of N<sub>d</sub>, as d tends to infinity. By deriving upper bounds and(More)
We consider a two polynomials analogue of the polynomial interpolation problem. Namely, we consider the Mixing Modular Operations (MMO) problem of recovering two polynomials <i>f</i> &#8712; Z<sub><i>p</i></sub>[<i>x</i>] and <i>g</i> &#8712; Z<sub><i>q</i></sub>[<i>x</i>] of known degree, where <i>p</i> and <i>q</i> are two (un)known positive integers,(More)
The future development of quantum-computers could turn many key agreement algorithms used in the Internet today fully insecure, endangering many applications such as online banking, e-commerce, e-health, etc. At the same time, the Internet is further evolving to enable the Internet of Things (IoT) in which billions of devices deployed in critical(More)
The HIMMO scheme has been introduced as a lightweight collusion-resistant key pre-distribution scheme, with excellent efficiency in terms of bandwidth, energy consumption and computation time. As its cryptanalysis relies on lattice techniques, HIMMO is also an interesting quantum-safe candidate. Unlike the schemes by Blom, by Matsumoto and Imai, and by(More)
Motivated by a recently introduced HIMMO key predistribution scheme, we investigate the limits of various attacks on the polynomial interpolation problem with mixed modular operations and hidden moduli. We firstly review the classical attack and consider it in a quantum-setting. Then, we introduce new techniques for finding out the secret moduli and(More)
Smart ob jects are devices with computational and communication capabilities connected to the Internet forming the so called Internet of Things (IoT). The IoT enables many applications, for instance outdoor lighting con­ trol, smart energy and water management, or environmental sensing in a smart city environment. Security in such scenarios remains an open(More)