Meltem Sonmez Turan

On Independence and Sensitivity of Statistical Randomness Tests

Statistical randomness testing has significant importance in analyzing the quality of random number generators. In this study, we focus on the independence of randomness tests and its effect on the coverage of test suites. We experimentally observe that frequency, overlapping template, longest run of ones, random walk height and maximum order complexity tests are correlated for short sequences. We also proposed the concept of sensitivity, where we analyze the effect of simple transformations on output p-values. We claim that whenever the effect is significant, the composition of the transformation and the test may be included to the suite as a new test.

New Distinguishers Based on Random Mappings against Stream Ciphers

Statistical randomness testing plays an important role in security analysis of cryptosystems. In this study, we aim to propose a new framework of randomness testing based on random mappings. Considering the probability distributions of coverage and ρ-lengths, we present three new distinguishers; (i) coverage test, (ii) ρ-test and (iii) DP-coverage test and applied them on Phase III Candidates of eSTREAM project. We experimentally observed some statistical weaknesses of Pomaranch using the coverage test.

An Evolutionary Approach for the TSP and the TSP with Backhauls

This chapter presents an evolutionary approach for solving the traveling salesman problem (TSP) and the TSP with backhauls (TSPB). We propose two evolutionary algorithms for solving the difficult TSPs. Our focus is on developing evolutionary operators based on conventional heuristics. We rely on a set of detailed computational experiments and statistical tests for developing an effective algorithm.