Algebraic Shift Register Sequences

By Mark Goresky, Institute for Advanced Study

e-mail: goresky at math dot ias dot edu     Home Page

and

Andrew Klapper, University of Kentucky

e-mail: klapper at cs dot uky dot edu     Home Page



This a draft of a book on many aspects of algebraic methods of generating pseudo-random sequences, focusing on  properties that may  in communications, especially cryptography and CDMA.  There are many sections that are still in flux and certainly many errors, so be warned.  You are welcome to download the book in its current state.  We ask only that you give us your feedback.

PDF file of the book (updated 10/14/09): Algebraic Feedback Shift Registers (3 Megabytes)

Table of Contents

Part I: Algebraic Preliminaries
    Chapter 1: Introduction
    Chapter 2: Abstract Algebra
        2.1 Group Theory
        2.2 Rings
        2.3 Characters and Fourier transforms
        2.4 Polynomials
        2.5 Exercises
    Chapter 3: Fields
        3.1 Field extensions
        3.2 Finite Fields
        3.3 Quadratic forms over a finite field
        3.4 Algebraic Number Fields
        3.5 Local and global fields
        3.6 Exercises
    Chapter 4: Finite Rings and Galois Rings
        4.1 Finite Local Rings   
        4.2 Examples    
        4.3 Divisibility in R[x]  
        4.4 Tools for Local Rings  
        4.5 Galois rings    
        4.6 Exercises    
    Chapter 5: Sequences, Power Series and Adic Rings
        5.1 Sequences     
        5.2 Power Series    
        5.3 Reciprocal Laurent series   
        5.4 N-Adic Numbers  
        5.5 π-Adic Numbers   
        5.6 Other constructions 
        5.7 Continued Fractions  
        5.8 Exercises    
Part II Algebraically Defined Sequences
    Chapter 6: Linear Feedback Shift Registers and Linear Recurrences
        6.1 Definitions    
        6.2 Matrix description 
        6.3 Initial loading
        6.4 Generating functions
        6.5 When the connection polynomial factors 
        6.6 Algebraic Models and the ring R[x]/(q) 
        6.7 Families of recurring sequences and ideals  
        6.8 Examples 
        6.9 Exercises
    Chapter 7: Feedback with Carry Shift Registers and Multiply with Carry Sequences
        7.1 Definitions   
        7.2 Analysis of FCSRs 
        7.3 Initial Loading 
        7.4 Representation of FCSR Sequences
        7.5 Example 
        7.6 Memory Requirements
        7.7 Random Number generation using MWC
        7.8 Exercises
    Chapter 8 Algebraic Feedback Shift Registerss
        8.1 Definitions 
        8.2 Properties of AFSRs
        8.3 Memory Requirements
        8.4 Periodicity 
        8.5 Exponential Representation and Period of AFSR Sequences   
        8.6 Examples  
        8.7 Exercises
    Chapter 9: d-FCSRs
        9.1 Binary d-FCSRs  
        9.2 General d-FCSRs  
        9.3 Relation Between the Norm and the Period
        9.4 Periodicity
        9.5 Elementary description of d-FCSR sequences
        9.6 An Example
        9.7 Exercises 
    Chapter 10: Galois mode and related circuits
        10.1 Galois mode LFSRs
        10.2 Division by q(x) in R[[x]]
        10.3 Galois mode FCSRs 
        10.4 Division by q in the N-adic numbers
        10.5 Galois mode d-FCSRs
        10.6 Linear register
        10.7 Exercises
Part III Pseudo-Random and Pseudo-Noise Sequences
    Chapter 11: Measures of pseudorandomness
        11.1 Why pseudo-random?
        11.2 Sequences based on an arbitrary alphabet
        11.3 Correlations     
        11.4 Exercises
    Chapter 12: Shift and add sequences
        12.1 Basic properties
        12.2 Characterization of shift and add sequences
        12.3 Examples of shift and add sequences
        12.4 Further properties of shift and add sequences 
        12.5 Proof of Theorem 12.3.1
        12.6 Arithmetic Shift and Add Sequences 
        12.7 Exercises 
    Chapter 13: m-Sequences
        13.1 Basic properties of m-sequences 
        13.2 Decimations
        13.3 Interleaved structure
        13.4 Fourier transforms and m-sequences 
        13.5 Cross-correlation of an m-sequence and its decimation
        13.6 The Diaconis mind-reader
        13.7 Exercises
    Chapter 14: Related Sequencesi and their Correlations
        14.1 Welch bound 
        14.2 Families derived from a decimation 
        14.3 Gold sequences 
        14.4 Kasami sequences, small set
        14.5 Geometric sequences
        14.6 GMW sequences
        14.7 d-form sequences 
        14.8 Legendre and Dirichlet sequences 
        14.9 Frequency hopping sequences
        14.10 Maximal sequences over a finite local ring ring 
        14.11 Exercises
    Chapter 15: Maximal Period Function Field Sequences
        15.1 The Rational function field AFSR
        15.2 Global function fields 
        15.3 Exercises
    Chapter 16: Maximal Period FCSRs
        16.1 l-Sequences
        16.2 Distributional properties of l-sequences
        16.3 Arithmetic correlations
        16.4 Tables
        16.5 Exercises
    Chapter 17: Maximal Period d-FCSRs
        17.1 Identifying maximal length sequences
        17.2 Distribution properties of d-l-Sequences
        17.3 Arithmetic correlation
        17.4 Exercises
Part IV Register Synthesis and Security Measures
    Chapter 18: Register Synthesis and LFSR Synthesis
        18.1 Sequence generators and the register synthesis problem 
        18.2 LFSRs and the Berlekamp-Massey algorithm 
        18.3 Blahut’s theorem
        18.4 The Gunther-Blahut theorem    
        18.5 Generating sequences with large linear span 
        18.6 Exercises    
    Chapter 19: FCSR Synthesis
        19.1 N-adic span and complexity
        19.2 Symmetric N-adic span
        19.3 Rational approximation
        19.4 Exercises
    Chapter 20: AFSR Synthesis
        20.1 Xu’s rational approximation algorithm
        20.2 Rational approximation in Z
        20.3 Proof of correctness
        20.4 Rational approximation in function fields  
        20.5 Rational approximation in ramified extensions  
        20.6 Rational approximation in quadratic extensions
        20.7 Rational approximation by interleaving
        20.8 Rational function fields: pi-adic vs. linear span
        20.9 Exercises
    Chapter 21: Average and Asymptotic Behavior of Security Measures
        21.1 Average behavior of linear complexity
        21.2 Average behavior of N-adic complexity
        21.3 Asymptotic behavior of security measures
        21.4 Asymptotic linear complexity
        21.5 Asymptotic N-adic complexity
        21.6 Consequences and questions
        21.7 Exercises