Encryption converts readable data into an unreadable form. Only someone with the correct key can reverse the process. The math has been around for decades. The implementation is where things go wrong. AES-256 is effectively unbreakable with current technology. A system using AES-256 with a weak password is not. Encryption is a tool, not a guarantee.

Encryption protects data at rest and in transit. Full-disk encryption protects a stolen laptop. TLS protects data moving between a browser and a server. End-to-end encryption protects messaging so that not even the service provider can read the contents. Each use case has different requirements. At rest, you need key management and secure storage. In transit, you need certificate validation and forward secrecy. For messaging, you need key verification to prevent man-in-the-middle attacks. Encryption is also a legal battleground. Governments want lawful access. Privacy advocates argue that any backdoor weakens the whole system. The debate has no clean resolution. What is clear is that unencrypted data is exposed data. If it is worth storing, it is worth encrypting.

Encryption in practice

• At rest — full-disk, database, and file-level encryption
• In transit — TLS for web, VPN for remote access
• End-to-end — messaging and email
• Key management — the hard part, not the algorithm

Encryption without key management is theater. The keys are the secret. Protect them like it.