Ronald Rietman

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Reducing the number of tag collisions is one of the most important issues in RFID systems, as collisions induce inefficiency. This paper presents a mechanism of grouping of tags via a bit mask, quick tag estimation by a pilot frame and near optimal binary tree-based collision resolution with a frame. Performance analysis and simulation results show that the(More)
An array of a large number of LEDs will be widely used in future indoor illumination systems. In this paper, we investigate the problem of rendering uniform illumination by a regular LED array on the ceiling of a room. We first present two general results on the scaling property of the basic illumination pattern, i.e., the light pattern of a single LED, and(More)
This paper introduces a new key establishment scheme aiming at fully collusion-resistant identity-based symmetric-key agreement. In an identitybased pairwise key agreement scheme, a Trusted Third Party (TTP) manages the system and securely provides any node, e.g., Alice or Bob, with private keying materials. Alice can generate a pairwise key with Bob given(More)
Light-emitting diodes (LEDs) will play a major role in future indoor illumination systems. In general, the generalized Lambertian pattern is widely used as the radiation pattern of a single LED. In this letter, we show that the illuminance distribution due to this Lambertian pattern, when projected onto a horizontal surface such as a floor, can be well(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) modulo a prime p at polynomially many points t taken from a short interval.
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)
In this paper we introduce HIMMO as a truly practical and lightweight collusion-resistant key predistribution scheme. The scheme is reminiscent of Blundo et al’s elegant key predistribution scheme, in which the master key is a symmetric bivariate polynomial over a finite field, and a unique common key is defined for every pair of nodes as the evaluation of(More)