Cryptography

Cryptography: The Art and Science of Secure Communication is a hands-on guide to applied cryptography for software engineers — not a math textbook, but a field manual for using cryptographic primitives correctly in real systems. Across twelve chapters, it builds from first principles (security goals, threat models, why classical ciphers fail) through the full modern toolkit: symmetric encryption and AEAD ciphers, hash functions and password hashing, message authentication codes, Diffie-Hellman and elliptic-curve key exchange, RSA, digital signatures, and the certificate infrastructure behind the web's trust model. A dedicated chapter on TLS and SSH shows how these primitives assemble into the protocols securing real traffic, and a chapter on cryptanalysis walks through historical breaks — including a complete, tested padding-oracle attack that recovers plaintext using nothing but a vulnerable server's yes/no answers. A closing chapter covers post-quantum cryptography and the migration already underway in production systems today. Every chapter pairs working Python code with a real-world failure case study — Sony's PS3 signing key recovered from two signatures, the DigiNotar certificate authority breach, the Logjam and POODLE attacks — so the lesson is never abstract. The book closes with a capstone project combining key exchange, key derivation, authenticated encryption, and digital signatures into one working design, plus a production checklist for shipping cryptographic features safely.