Foreword Preface About the Author Aperitifs The Lexicon of Cryptography Cryptographic Systems Cryptanalysis Side Information Thomas Jefferson and the

Transcription

1 Foreword Preface About the Author Aperitifs The Lexicon of Cryptography Cryptographic Systems Cryptanalysis Side Information Thomas Jefferson and the M-94 Cryptography and History Cryptography and Computers The National Security Agency The Giants No Sex, Money, Crime or... Love An Example of the Inference Process in Cryptanalysis Warning! Columnar Transposition Shannon?s Classification of Secrecy Transformations The Rules of Columnar Transposition Encipherment Cribbing Examples of Cribbing Plaintext Language Models Counting k-grams Deriving the Parameters of a Markov Model from Sliding Window Counts Markov Scoring The ADFGVX Transposition System CODA Columnar Transposition Problems Monoalphabetic Substitution Monoalphabetic Substitution Caesar's Cipher Cribbing Using Isomorphs The x2-test of a Hypothesis Pruning from the Table of Isomorphs Partial Maximum Likelihood Estimation of a Monoalphabetic Substitution The Hidden Markov Model (HMM) Hill Encipherment of ASCII N-Grams Gaussian Elimination Monoalphabetic Substitution Problems Polyalphabetic Substitution Running Keys

2 Blaise de Vigenére Gilbert S. Vernam The One-Time Pad Finding the Key of Vernam-Vigenére Ciphertext with Known Period by Correlation Coincidence Venona Polyalphabetic Substitution Problems Statistical Tests Weaknesses in a Cryptosystem The Kolmogorov-Smirnov Test NIST's Proposed Statistical Tests Diagnosis Statistical Tests Problems The Emergence Of Cipher Machines The Rotor Rotor Systems Rotor Patents A Characteristic Property of Conjugacy Analysis of a 1-Rotor System Ciphertext Only The Displacement Sequence of a Permutation Arthur Scherbius Enigma Key Distribution Protocol Cryptanalysis of the Enigma Cribbing Enigma Ciphertext The Lorenz Schlüsselzusatz The SZ40 Pin Wheels SZ40 Cryptanalysis Problems Cribbing SZ40 Ciphertext The Japanese Cipher Machines Japanese Signaling Conventions Half-Rotors Components of the RED Machine Cribbing RED Ciphertext Generalized Vowels and Consonants "Climb Mount Itaka" - War! Components of the PURPLE Machine The PURPLE Keys Cribbing PURPLE Finding the V-Stepper Cribbing PURPLE Finding the C-Steppers Stream Ciphers Stream Ciphers

3 Feedback Shift Registers The Algebra of Polynomials over Z2 The Characteristic Polynomial of a Linear Feedback Shift Register Properties of Maximal Length LFSR Sequences Linear Equivalence Combining Multiple Linear Feedback Shift Registers Matrix Representation of the LFSR Cribbing of Stream Enciphered ASCII Plaintext Nonlinear Feedback Shift Registers Nonlinear Key Stream Generation Irregular Clocking RC4 Stream Encipherment Problems Block-Ciphers Clucifer, Des, And Aes Lucifer Des The DES S-Boxes, P-Box, and Initial Permutation (IP) DES Key Schedule Sample DES Encipherment Chaining Is DES a Random Mapping? DES in the Output-Feedback Mode (OFB) Cryptanalysis of DES Differential Cryptanalysis The EFS DES-Cracker What Now? The Future Advanced Data Encryption Standard And the Winner Is! The Rijndael Operations The Rijndael Cipher Rijndael's Strength Propagation of Patterns When is a Product Block-Cipher Secure? Generating the Symmetric Group A Class of Block Ciphers The IDEA Block Cipher The Paradigm Of Public Key Cryptography In the Beginning.. Key Distribution E-Commerce Public-Key Cryptosystems Easy and Hard Computational Problems Do PKCS Solve the Problem of Key Distribution?

4 P.S The Knapsack Cryptosystem Subset Sum and Knapsack Problems Modular Arithmetic and the Euclidean Algorithm A Modular Arithmetic Knapsack Problem Trap-Door Knapsacks Knapsack Encipherment and Decipherment of ASCII-Plaintext Cryptanalysis of the Merkle-Hellman Knapsack System Modular Mapping Diophantine Approximation Short Vectors in a Lattice Knapsack-Like Cryptosystems Knapsack Cryptosystem Problems The Rsa Cryptosystem A Short Number-Theoretic Digression RSA The RSA Encipherment and Decipherment of ASCII-Plaintext Attack on RSA Williams Variation of RSA Multiprecision Modular Arithmetic Prime Numbers And Factorization Number Theory and Cryptography Prime Numbers and the Sieve of Eratosthenes Pollard's p 2 1 Method Pollard's r-algorithm Quadratic Residues Random Factorization The Quadratic Sieve (QS) Testing if an Integer is a Prime The RSA Challenge Perfect Numbers and the Mersenne Primes Multiprecision Arithmetic Prime Number Testing and Factorization Problems The Discrete Logarithm Problem The Discrete Logarithm Problem Modulo p Solution of the DLP Modulo p Given a Factorization of p 2 1 Adelman's Subexponential Algorithm for the Discrete Logarithm Problem The Baby-Step, Giant-Step Algorithm The Index-Calculus Method Pollard's r -Algorithm Extension Fields The Current State of Discrete Logarithm Research

5 Elliptic Curve Cryptography Elliptic Curves The Elliptic Group over the Reals Lenstra's Factorization Algorithm The Elliptic Group over Zp ( p. 3) Elliptic Groups over the Field Zm,2 Computations in the Elliptic Group EZm,2(a, b) Supersingular Elliptic Curves Diffie-Hellman Key Exchange Using an Elliptic Curve The Menezes-Vanstone Elliptic Curve Cryptosystem The Elliptic Curve Digital Signature Algorithm The Certicom Challenge NSA and Elliptic Curve Cryptography Key Exchange In A Network Key Distribution in a Network U.S. Patent '770 Spoofing El Gamal's Extension of Diffie-Hellman Shamir's Autonomous Key Exchange X9.17 Key Exchange Architecture The Needham-Schroeder Key Distribution Protocol Digital Signatures And Authentication The Need for Signatures Threats to Network Transactions Secrecy, Digital Signatures, and Authentication The Desiderata of a Digital Signature Public-Key Cryptography and Signature Systems Rabin's Quadratic Residue Signature Protocol Hash Functions MD5 The Secure Hash Algorithm NIST's Digital Signature Algorithm El Gamal's Signature Protocol The Fiat-Shamir Identification and Signature Schema The Oblivious Transfer Applications Of Cryptography UNIX Password Encipherment Magnetic Stripe Technology Protecting ATM Transactions Keyed-Access Cards Smart Cards

6 Who Can You Trust? Kohnfelder's Certificates X.509 Certificates The Secure Socket Layer (SSL) Making a Secure Credit Card Payment on the Web Cryptographic Patents What is a Patent? Patentability of Ideas The Format of a Patent Patentable versus Nonpatentable Subjects Infringement The Role of Patents in Cryptography U.S. Patent 3,543,904 U.S. Patent 4,200,770 U.S. Patent 4,218,582 U.S. Patent 4,405,829 PKS/RSADSI Litigation Leon Stambler Index Table of Contents provided by Blackwell's Book Services and R.R. Bowker. Used with permission.