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| Introduction to Cryptography and Data Security | |
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| Overview of Cryptography (and This Book) | |
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| Symmetric Cryptography | |
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| Basics | |
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| Simple Symmetric Encryption: The Substitution Cipher | |
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| Cryptanalysis | |
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| General Thoughts on Breaking Cryptosystems | |
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| How Many Key Bits Are Enough? | |
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| Modular Arithmetic and More Historical Ciphers | |
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| Modular Arithmetic | |
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| Integer Rings | |
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| Shift Cipher (or Caesar Cipher) | |
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| Affine Cipher | |
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| Discussion and Further Reading | |
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| Lessons Learned | |
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| Problems | |
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| Stream Ciphers | |
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| Introduction | |
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| Stream Ciphers vs. Block Ciphers | |
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| Encryption and Decryption with Stream Ciphers | |
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| Random Numbers and an Unbreakable Stream Cipher | |
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| Random Number Generators | |
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| The One-Time Pad | |
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| Towards Practical Stream Ciphers | |
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| Shift Register-Based Stream Ciphers | |
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| Linear Feedback Shift Registers (LFSR) | |
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| Known-Plaintext Attack Against Single LFSRs | |
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| Trivium | |
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| Discussion and Further Reading | |
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| Lessons Learned | |
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| Problems | |
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| The Data Encryption Standard (DES) and Alternatives | |
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| Introduction to DES | |
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| Confusion and Diffusion | |
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| Overview of the DES Algorithm | |
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| Internal Structure of DES | |
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| Initial and Final Permutation | |
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| The �-Function | |
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| Key Schedule | |
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| Decryption | |
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| Security of DES | |
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| Exhaustive Key Search | |
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| Analytical Attacks | |
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| Implementation in Software and Hardware | |
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| DES Alternatives | |
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| The Advanced Encryption Standard (AES) and the AES Finalist Ciphers | |
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| Triple DES (3DES) and DESX | |
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| Lightweight Cipher PRESENT | |
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| Discussion and Further Reading | |
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| Lessons Learned | |
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| Problems | |
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| The Advanced Encryption Standard (AES) | |
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| Introduction | |
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| Overview of the AES Algorithm | |
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| Some Mathematics: A Brief Introduction to Galois Fields | |
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| Existence of Finite Fields | |
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| Prime Fields | |
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| Extension Fields GF(2m) | |
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| Addition and Subtraction in GF(2m) | |
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| Multiplication in GF{2m) | |
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| Inversion in GF(2m) | |
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| Internal Structure of AES | |
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| Byte Substitution Layer | |
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| Diffusion Layer | |
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| Key Addition Layer | |
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| Key Schedule | |
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| Decryption | |
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| Implementation in Software and Hardware | |
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| Discussion and Further Reading | |
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| Lessons Learned | |
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| Problems | |
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| More About Block Ciphers | |
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| Encryption with Block Ciphers: Modes of Operation | |
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| Electronic Codebook Mode (ECB) | |
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| Cipher Block Chaining Mode (CBC) | |
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| Output Feedback Mode (ORB) | |
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| Cipher Feedback Mode (CFB) | |
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| Counter Mode (CTR) | |
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| Galois Counter Mode (GCM) | |
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| Exhaustive Key Search Revisited | |
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| Increasing the Security of Block Ciphers | |
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| Double Encryption and Meet-in-the-Middle Attack | |
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| Triple Encryption | |
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| Key Whitening | |
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| Discussion and Further Reading | |
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| Lessons Learned | |
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| Problems | |
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| Introduction to Public-Key Cryptography | |
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| Symmetric vs. Asymmetric Cryptography | |
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| Practical Aspects of Public-Key Cryptography | |
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| Security Mechanisms | |
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| The Remaining Problem: Authenticity of Public Keys | |
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| Important Public-Key Algorithms | |
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| Key Lengths and Security Levels | |
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| Essential Number Theory for Public-Key Algorithms | |
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| Euclidean Algorithm | |
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| Extended Euclidean Algorithm | |
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| Euler's Phi Function | |
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| Fermat's Little Theorem and Euler's Theorem | |
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| Discussion and Further Reading | |
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| Lessons Learned | |
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| Problems | |
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| The RSA Cryptosystem | |
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| Introduction | |
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| Encryption and Decryption | |
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| Key Generation and Proof of Correctness | |
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| Encryption and Decryption: Fast Exponentiation | |
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| Speed-up Techniques for RSA | |
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| Fast Encryption with Short Public Exponents | |
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| Fast Decryption with the Chinese Remainder Theorem | |
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| Finding Large Primes | |
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| How Common Are Primes? | |
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| Primality Tests | |
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| RSA in Practice: Padding | |
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| Attacks | |
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| Implementation in Software and Hardware | |
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| Discussion and Further Reading | |
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| Lessons Learned | |
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| Problems | |
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| Public-Key Cryptosystems Based on the Discrete Logarithm Problem | |
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| Difne-Hellman Key Exchange | |
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| Some Algebra | |
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| Groups | |
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| Cyclic Groups | |
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| Subgroups | |
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| The Discrete Logarithm Problem | |
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| The Discrete Logarithm Problem in Prime Fields | |
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| The Generalized Discrete Logarithm Problem | |
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| Attacks Against the Discrete Logarithm Problem | |
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| Security of the Difne-Hellman Key Exchange | |
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| The Elgamal Encryption Scheme | |
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| From Difne-Hellman Key Exhange to Elgamal Encryption | |
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| The Elgamal Protocol | |
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| Computational Aspects | |
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| Security | |
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| Discussion and Further Reading | |
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| Lessons Learned | |
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| Problems | |
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| Elliptic Curve Cryptosystems | |
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| How to Compute with Elliptic Curves | |
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| Definition of Elliptic Curves | |
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| Group Operations on Elliptic Curves | |
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| Building a Discrete Logarithm Problem with Elliptic Curves | |
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| Difne-Hellman Key Exchange with Elliptic Curves | |
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| Security | |
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| Implementation in Software and Hardware | |
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| Discussion and Further Reading | |
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| Lessons Learned | |
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| Problems256 | |
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| Digital Signatures | |
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| Introduction | |
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| Odd Colors for Cars, or: Why Symmetric Cryptography Is Not Sufficient | |
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| Principles of Digital Signatures | |
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| Security Services | |
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| The RSA Signature Scheme | |
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| Schoolbook RSA Digital Signature | |
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| Computational Aspects | |
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| Security | |
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| The Elgamal Digital Signature Scheme | |
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| Schoolbook Elgamal Digital Signature | |
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| Computational Aspects | |
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| Security | |
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| The Digital Signature Algorithm (DSA) | |
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| The DSA Algorithm | |
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| Computational Aspects | |
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| Security | |
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| The Elliptic Curve Digital Signature Algorithm (ECDSA) | |
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| The ECDSA Algorithm | |
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| Computational Aspects | |
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| Security | |
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| Discussion and Further Reading | |
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| Lessons Learned | |
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| Problems | |
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| Hash Functions | |
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| Motivation: Signing Long Messages | |
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| Security Requirements of Hash Functions | |
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| Preimage Resistance or One-Wayness | |
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| Second Preimage Resistance or Weak Collision Resistance | |
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| Collision Resistance and the Birthday Attack | |
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| Overview of Hash Algorithms | |
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| Dedicated Hash Functions: The MD4 Family | |
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| Hash Functions from Block Ciphers | |
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| The Secure Hash Algorithm SHA-1 | |
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| Preprocessing | |
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| Hash Computation | |
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| Implementation | |
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| Discussion and Further Reading | |
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| Lessons Learned | |
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| Problems | |
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| Message Authentication Codes (MACs) | |
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| Principles of Message Authentication Codes | |
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| MACs from Hash Functions: HMAC | |
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| MACs from Block Ciphers: CBC-MAC | |
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| Galois Counter Message Authentication Code (GMAC) | |
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| Discussion and Further Reading | |
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| Lessons Learned | |
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| Problems | |
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| Key Establishment | |
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| Introduction | |
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| Some Terminology | |
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| Key Freshness and Key Derivation | |
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| The n2 Key Distribution Problem | |
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| Key Establishment Using Symmetric-Key Techniques | |
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| Key Establishment with a Key Distribution Center | |
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| Kerberos | |
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| Remaining Problems with Symmetric-Key Distribution | |
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| Key Establishment Using Asymmetric Techniques | |
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| Man-in-the-Middle Attack | |
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| Certificates | |
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| Public-Key Infrastructures (PKI) and CAs | |
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| Discussion and Further Reading | |
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| Lssons Learned | |
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| Problems | |
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| References | |
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| Index | |