This is a graduate-level course on cryptography. It focuses on the definitions and constructions of various cryptographic schemes and protocols, as well as their applications. Useful tools for securing practical systems and emerging techniques in the applied research community will be introduced. No prior knowledge of security, cryptography, or number theory is required.- Introduction: a brief history, applications in distributed systems; basic number theory- Symmetric-key encryption: definition, information-theoretic security, Entropy, PRNG- Provable security: bounded adversary, random oracle model, basic primitives, reduction- Public-key encryption: modelling security, Diffie-Hellman protocol, hybrid encryption- Authentication: Hash function, collision-resistance, MAC, unforgeability- Public-key infrastructure: certificate management, deployment, and revocation issues- More schemes: Fiat-Shamir transformation, Cramer-Shoup encryption, identity-/attribute-based encryption, certificateless encryption, proxy re-encryption , broadcast- Privacy-enhancing cryptography: zero-knowledge proof, anonymous credentials- Pairing-based cryptography: elliptic curve basic, short signature, searchable encryption