Security architecture principles

Security requires defense in depth — multiple barriers that each handle different attack vectors. When one defense fails, others maintain protection. This redundancy prevents single points of failure from exposing entire systems.

Core protections start with encryption. TLS/HTTPS secures data in transit between clients and servers. At-rest encryption protects stored data. Password hashing ensures that database breaches don't expose user credentials. Each layer serves a specific purpose in the security chain.

Authentication verifies identity while authorization controls access. Modern apps often delegate authentication to specialized providers through protocols like OAuth 2.0. This lets users authenticate with Google or GitHub without sharing credentials with your app. It's more secure and users find it easier than creating another password.