Chapter 1. Introduction to Cyber Security.- Chapter 2. Cryptography Concepts: Confidentiality.- Chapter 3. Cryptography Concepts: Integrity, Authentication, Availability, Access Control, Non-Repudiation .- Chapter 4. New Trends in Cryptography: Quantum, Blockchain, Lightweight, Chaotic and DNA Cryptography.- Chapter 5. Data Hiding: Steganography and Watermarking.- Chapter 6. Conclusions.