Radio networks (RN) are distributed systems (ad hoc networks) consisting in n ≥ 2 radio stations. Assuming the number n unknown, two distinct models of RN without collision detection (no-CD) are addressed: the model with weak no-CD RN and the one with strong no-CD RN. We design and analyze two distributed leader election protocols, each one running in each of the above two (no-CD RN) models, re...

We find generating functions for the number of strings (words) containing a specified number of occurrences of certain types of order-isomorphic classes of substrings called subword patterns. In particular, we find generating functions for the number of strings containing a specified number of occurrences of a given 3-letter subword pattern.

We prove that the 5-round iterated Even-Mansour (IEM) construction with a non-idealized key-schedule (such as the trivial keyschedule, where all round keys are equal) is indifferentiable from an ideal cipher. In a separate result, we also prove that five rounds are necessary by describing an attack against the corresponding 4-round construction. This closes the gap regarding the exact number of...

Recently a powerful cryptanalytic tool—the slide attack— was introduced [3]. Slide attacks are very successful in breaking iterative ciphers with a high degree of self-similarity and even more surprisingly are independent of the number of rounds of a cipher. In this paper we extend the applicability of slide attacks to a larger class of ciphers. We find very efficient knownand chosen-text attac...

We show how to construct an ideal cipher with n-bit blocks and n-bit keys (i.e. a set of 2 public n-bit permutations) from a small constant number of n-bit random public permutations. The construction that we consider is the single-key iterated Even-Mansour cipher, which encrypts a plaintext x ∈ {0, 1} under a key k ∈ {0, 1} by alternatively xoring the key k and applying independent random publ...

The main purpose of this paper is to look at the notion of partial transpose from the combinatorial side. In this perspective, we solve some basic enumeration problems involving partial transpose of permutation matrices. Specifically, we count the number of permutations matrices which are invariant under partial transpose. We count the number of permutation matrices which are still permutation ...

IEEE Trans. Circuits Syst II, vol. 48, no. 3, pp. 233{244, March 2001 Stability and Performance Analysis of an Adaptive Sigma Delta Modulator Mansour A. Aldajani, Student Member, IEEE, and Ali H. Sayed, Fellow, IEEE Abstract| This work develops an adaptive sigma delta modulator that is based on adapting the quantizer stepsize using estimates of the quantizer input rather than the modulator inpu...

We present two extensions of the linear bound, due to Marcus and Tardos, on the number of 1’s in an n × n 0-1 matrix avoiding a fixed permutation matrix. We first extend the linear bound to hypergraphs with ordered vertex sets and, using previous results of Klazar, we prove an exponential bound on the number of hypergraphs on n vertices which avoid a fixed permutation. This, in turn, solves var...

Abstr(~ct-The definition of an N-D discrete time lossless bounded real (DTLBR) matrix and sufticient conditions on a state space representation to correspond to an N-D DTLBR matrix are given. Based on these suEcient conditions, it is shown that the transfer function of the n-D lattice filter, which is obtained fmm a stable 1-D lattice filter by replacing each delay element r *th z, (i = 1.2,. ....