Now showing items 1-10 of 49
The sizes of optimal q-ary codes of weight three and distance four : a complete solution
This correspondence introduces two new constructive techniques to complete the determination of the sizes of optimal q-ary codes of constant weight three and distance four.
Improved lower bounds for constant GC-content DNA codes
The design of large libraries of oligonucleotides having constant GC-content and satisfying Hamming distance constraints between oligonucleotides and their Watson-Crick complements is important in reducing hybridization ...
The PBD-closure of constant-composition codes
We show an interesting pairwise balanced design (PBD)-closure result for the set of lengths of constant-composition codes whose distance and size meet certain conditions. A consequence of this PBD-closure result is that ...
Constructions for q-ary constant-weight codes
This paper introduces a new combinatorial construction for q-ary constant-weight codes which yields several families of optimal codes and asymptotically optimal codes. The construction reveals intimate connection between ...
Linear size optimal q-ary constant-weight codes and constant-composition codes
An optimal constant-composition or constant-weight code of weight w has linear size if and only if its distance d is at least 2w-1. When d ≥ 2w, the determination of the exact size of such a constant-composition or ...
Cycle systems in the complete bipartite graph plus a one-factor
Let Kn,n denote the complete bipartite graph with n vertices in each partite set and Kn,n+I denote Kn,n with a one-factor added. It is proved in this paper that there exists an m-cycle system ...
Improved p-ary codes and sequence families from Galois rings of characteristic p2
This paper explores the applications of a recent bound on some Weil-type exponential sums over Galois rings in the construction of codes and sequences. A family of codes over Fp, mostly nonlinear, of length pm+1 and size ...
Aperiodic and odd correlations of some p-ary sequences from Galois rings
We obtain an upper bound for the maximum aperiodic and odd correlations of the recently derived p-ary sequences from Galois rings . We use the upper bound on hybrid sums over Galois rings , the Vinogradov method  ...
Practical pseudo-collisions for hash functions ARIRANG-224/384
In this paper we analyse the security of the SHA-3 candidate ARIRANG. We show that bitwise complementation of whole registers turns out to be very useful for constructing high-probability differential characteristics in ...
Cryptanalysis of the LAKE hash family
We analyse the security of the cryptographic hash function LAKE-256 proposed at FSE 2008 by Aumasson, Meier and Phan. By exploiting non-injectivity of some of the building primitives of LAKE, we show three different collision ...