This book constitutes the refereed proceedings of the 4th International Conference on Sequences and Their Applications, SETA 2006. The book presents 32 revised full papers together with 4 invited lectures. The papers are organized in topical sections on linear complexity of sequences, correlation of sequences, stream ciphers and transforms, topics in complexities of sequences, multi-sequence synthesis, sequences and combinatorics, FCSR sequences, aperiodic correlation and applications, and boolean functions, and more.

Invited Papers.- Shift Register Sequences - A Retrospective Account.- The Probabilistic Theory of the Joint Linear Complexity of Multisequences.- Multi-Continued Fraction Algorithms and Their Applications to Sequences.- Codes for Optical CDMA.- Linear Complexity of Sequences.- On the Linear Complexity of Sidel'nikov Sequences over .- Linear Complexity over F p of Ternary Sidel'nikov Sequences.- Bounds on the Linear Complexity and the 1-Error Linear Complexity over F p of M-ary Sidel'nikov Sequences.- The Characterization of 2 n -Periodic Binary Sequences with Fixed 1-Error Linear Complexity.- Correlation of Sequences.- Crosscorrelation Properties of Binary Sequences with Ideal Two-Level Autocorrelation.- Extended Hadamard Equivalence.- Analysis of Designing Interleaved ZCZ Sequence Families.- Stream Ciphers and Transforms.- Security of Jump Controlled Sequence Generators for Stream Ciphers.- Improved Rijndael-Like S-Box and Its Transform Domain Analysis.- Topics in Complexities of Sequences.- Nonlinear Complexity of Binary Sequences and Connections with Lempel-Ziv Compression.- On Lempel-Ziv Complexity of Sequences.- Computing the k-Error N-Adic Complexity of a Sequence of Period p n .- On the Expected Value of the Joint 2-Adic Complexity of Periodic Binary Multisequences.- Linear/Nonlinear Feedback Shift Register Sequences.- On the Classification of Periodic Binary Sequences into Nonlinear Complexity Classes.- Sequences of Period 2 N -2.- A New Algorithm to Compute Remote Terms in Special Types of Characteristic Sequences.- Multi-sequence Synthesis.- Implementation of Multi-continued Fraction Algorithm and Application to Multi-sequence Linear Synthesis.- The Hausdorff Dimension of the Set of r-Perfect M-Multisequences.- Filtering Sequences andPseudorandom Sequence Generators.- Lower Bounds on Sequence Complexity Via Generalised Vandermonde Determinants.- Construction of Pseudo-random Binary Sequences from Elliptic Curves by Using Discrete Logarithm.- On the Discrepancy and Linear Complexity of Some Counter-Dependent Recurrence Sequences.- Sequences and Combinatorics.- Nonexistence of a Kind of Generalized Perfect Binary Array.- FCSR Sequences.- On the Distinctness of Decimations of Generalized l-Sequences.- On FCSR Memory Sequences.- Periodicity and Distribution Properties of Combined FCSR Sequences.- Aperiodic Correlation and Applications.- Generalized Bounds on Partial Aperiodic Correlation of Complex Roots of Unity Sequences.- Chip-Asynchronous Version of Welch Bound: Gaussian Pulse Improves BER Performance.- Boolean Functions.- On Immunity Profile of Boolean Functions.- Reducing the Number of Homogeneous Linear Equations in Finding Annihilators.- The Algebraic Normal Form, Linear Complexity and k-Error Linear Complexity of Single-Cycle T-Function.- Partially Perfect Nonlinear Functions and a Construction of Cryptographic Boolean Functions.- Construction of 1-Resilient Boolean Functions with Very Good Nonlinearity.