Quantum-Safe Cryptography: How Encryption Evolved and Why It Needs to Evolve Again

A software engineer's accessible explanation of quantum-safe cryptography, covering the history of encryption from Caesar ciphers to RSA and ECC, how Shor's algorithm threatens asymmetric cryptography, and why the 'harvest now, decrypt later' threat is already relevant. Explains post-quantum alternatives like lattice-based cryptography and the NIST-standardized ML-KEM algorithm. Includes practical guidance for Java/JVM developers using Bouncy Castle to experiment with ML-KEM today, plus a migration strategy covering auditing, hybrid approaches, and prioritizing long-lived sensitive data.