Practical Cryptography for Developers

A modern practical book about cryptography for developers with code examples, covering core concepts like: hashes (like SHA-3 and BLAKE2), MAC codes (like HMAC and GMAC), key derivation functions (like Scrypt, Argon2), key agreement protocols (like DHKE, ECDH), symmetric ciphers (like AES and ChaCha20, cipher block modes, authenticated encryption, AEAD, AES-GCM, ChaCha20-Poly1305), asymmetric ciphers and public-key cryptosystems (RSA, ECC, ECIES), elliptic curve cryptography (ECC, secp256k1, curve25519), digital signatures (ECDSA and EdDSA), secure random numbers (PRNG, CSRNG) and quantum-safe cryptography, along with crypto libraries and developer tools, with a lots of code examples in Python and other languages.

This book covers the most important modern cryptographic concepts, crypto algorithms and cryptographic constructions, used in the software industry:
- Cryptographic hash functions: concepts, SHA-2, SHA-3, BLAKE2, RIPEMD160, code examples, collisions
- MAC codes: concepts, HMAC, CMAK, UMAC, applications, MAC-based random generators, code examples
- Key derivation functions (KDF): concepts, from password to encryption key, PBKDF2, Scrypt, Bcrypt, Linux crypt(), Argon2, code examples
- Password encryption techniques: from clear text, through hashing, to modern secure KDFs like Argon2
- Random numbers and secure random generators: concepts, entropy, secure random numbers, CSPRNG, code examples
- Key exchange techniques: key establishment and key agreement, Diffie–Hellman Key Exchange (DHKE) and Elliptic Curve Diffie–Hellman (ECDH) with code examples
- Encryption concepts: symmetric and asymmetric ciphers, secret keys, symmetric encryption, encryption schemes, public-key cryptosystems, private and public keys, hybrid encryption, digital signatures
- Modern symmetric key ciphers: concepts, block ciphers and stream ciphers, cipher block modes (CBC, CTR, GCM), the AES (Rijndael) cipher, the Salsa20 / ChaCha20 ciphers, with code examples
- Symmetric encryption constructions: authenticated encryption, AES-256-GCM, ChaCha20-Poly1307, AES-256-CTR-HMAC, with code examples
- Asymmetric key ciphers and public-key cryptosystems: the RSA cryptosystem (RSA key pairs, encryption, decryption), ECC (elliptic curve cryptography, EC points and multiplication, named curves), ECDH (elliptic-curve Diffie–Hellman) key exchange, code examples
- Elliptic curves: widely used named curves like secp256k1, P-256, P-521, Curve25519, Curve448-Goldilocks, with code examples
Integrated encryption schemes: combining public-key cryptography with symmetric encryption algorithms, the ECIES hybrid encryption scheme, with code examples
- Digital signature algorithms: concepts, signing messages, verifying signatures, RSA signatures, ECDSA and EdDSA
- Quantum-safe cryptography: which classical cryptosystems are quantum-broken and which are quantum-safe, quantum-safe signatures and quantum-safe key exchange algorithms, SPHINCS+, NewHope and others, with code examples
- Other cryptographic concepts: digital certificates, TLS (Transport Layer Security), one-time passwords (OTP), external authentication and OAuth
- Crypto libraries and packages for developers: cryptography in JavaScript, C#, Java, Python, C and C++
- A lot of code examples and exercises, following each major section

The book is free, published under the MIT license. Read the book for free from its Web site: https://cryptobook.nakov.com.