ABSTRACT

This chapter introduces the chaos-based technology for image cryptography, and presents examples with its applications in biometric protection for security system to show its performance. It discusses the issues and challenges in image cryptography, comparing with the traditional cryptography methodology. The chapter provides the results of related tests and analysis on key space, sensitivity, correlation and uniform distribution strategy with various biometric data and comparative analysis of their performance. It examines some typical methods for encryption including logistic mapping, tent mapping, sine mapping, Sawtooth-Bernoulli mapping, Gaussian mapping and their aperiodic domain. The hyperchaotic map can be used to enhance the chaos dynamics. However, hyperchaotic systems usually are based on the multidimensional chaos map. The chapter explores biometrics encryption as a case to study the feasibility and application of the chaotic image cryptography.