Everything Software Developers Need to Know About Cryptography

Cryptography is the foundation of digital trust. This guide breaks down its four pillars—confidentiality, integrity, authentication and non-repudiation—while explaining symmetric and asymmetric encryption, hash functions, MACs and digital signatures. It also highlights real-world applications, from TLS and Git to cryptocurrencies, and closes with essential security best practices: avoid weak algorithms, follow NIST standards, and never build your own crypto for production.