Malicious Cryptography: Exposing Cryptovirology

Contents

Foreword

Acknowledgments

Introduction

1 Through Hacker's Eyes

2 Cryptovirology

3 Tools for Security and Insecurity

3.1 Sources of Entropy

3.2 Entropy Extraction via Hashing

3.3 Unbiasing a Biased Coin

3.3.1 Von Neumann's Coin Flipping Algorithm

3.3.2 Iterating Neumann's Algorithm

3.3.3 Heuristic Bias Matching

3.4 Combining Weak Sources of Entropy

3.5 Pseudorandom Number Generators

3.5.1 Heuristic Pseudorandom Number Generation

3.5.2 PRNGs Based on Reduction Arguments

3.6 Uniform Sampling

3.7 Random Permutation Generation

3.7.1 Shuffling Cards by Repeated Sampling

3.7.2 Shuffling Cards Using Trotter-Johnson

3.8 Sound Approach to Random Number Generation and Use

3.9. RNGs Are the Beating Heart of System Security

3.10. Cryptovirology Benefits from General Advances

3.10.1 Strong Crypto Yields Strong Cryptoviruses

3.10.2 Mix Networks and Cryptovirus Extortion

3.11. Anonymizing Program Propagation

4 The Two Faces of Anonymity

4.1 Anonymity in a Digital Age

4.1.1 From Free Elections to the Unabomber

4.1.2 Electronic Money and Anonymous Payments

4.1.3 Anonymous Assassination Lotteries

4.1.4 Kidnapping and Perfect Crimes

4.1.5 Conducting Criminal Operations with Mixes

4.2 Deniable Password Snatching

4.2.1 Password Snatching and Security by Obscurity

4.2.2 Solving the Problem Using Cryptovirology

4.2.3 Zero-Knowledge Proofs to the Rescue

4.2.4 Improving the Attack Using ElGamal

5 Cryptocounters

5.1 Overview of Cryptocounters

5.2 Implementing Cryptocounters

5.2.1 A Simple Counter ...