Chap. 1 Basic Concepts and Historical Overview.- Chap. 2 Mathematical Foundations of Cryptography.- Chap. 3 Foundations of Symmetric Cryptography.- Chap. 4 Foundations of Asymmetric Cryptography.- Chap. 5 An Electronic Signature and Hash Functions.- Chap. 6 PGP Systems and True Crypt.- Chap. 7 Public Key Infrastructure.- Chap. 8 Cryptographic Protocols.- Chap. 9 Cryptography Application for Data Security.- References.- Index.