From Passwords to Tokens: How Web Authentication Has Evolved Over Time

Modern authentication methods each emerged to solve specific limitations of their predecessors, tracing a clear line from simple credential passing to stateless token systems. HTTP Basic Authentication, the earliest approach, transmitted base64-encoded passwords with every request, exposing credentials to interception, scaling issues, and an inability to revoke access selectively. Session-based authentication improved on this by verifying credentials only once at login, issuing the client a session ID via a cookie for all subsequent requests. However, sessions introduced server-side state management challenges, synchronization problems across multiple servers, and vulnerability to cross-site request forgery (CSRF) attacks. Sessions also proved ill-suited for non-browser environments like mobile apps and server-to-server communication, paving the way for token-based authentication approaches.