PASETO Tokens

"PASETO Tokens: Safer Alternatives to JWT for Modern Services"
Stateless tokens power modern microservices, mobile backends, and third‑party integrations—but the difference between “works” and “secure” is usually hidden in small validation choices and operational details. This book is written for experienced engineers and security-minded architects who have shipped JWT-based systems and want a clearer, safer model for token security that holds up under real adversaries, messy trust boundaries, and production constraints.
You’ll build a rigorous foundation for reasoning about bearer tokens, then dissect common JWT/JOSE failure modes—algorithm agility, ambiguous validation, and confused verifiers—to understand why teams repeatedly get them wrong. From there, the book teaches PASETO’s goals, token anatomy, purposes (local vs public), and version selection, followed by an implementation-level deep dive into v4 cryptography, PAE, footers, and implicit assertions for context binding. It then moves beyond cryptographic validity into semantic safety: claim schema design, strict parsing, mandatory validation rules, and misuse-resistant verifier APIs.
Finally, you’ll learn to operate PASETO in production: key custody and rotation, PASERK-based key distribution, replay-risk compensating controls, and a migration/testing playbook with official vectors, negative tests, telemetry, and incident response. Familiarity with distributed systems, basic applied cryptography, and secure software practices is assumed; the focus is on durable decision criteria and operational correctness.