Interactive Demo

Try the DCA demo with these articles. Each article has a free preview and encrypted premium content. Unlock them to see DCA in action.

🔐 DCA Mode: Content is encrypted server-side using HKDF-derived period keys with 1-hour rotation. Articles are grouped intotiers via contentName — articles in the same tier share period keys and can auto-unlock each other.

Demo Articles

Each article has a free preview and encrypted premium content. TierA and TierB use separate period keys — unlocking one tier does not grant access to the other.

The Complete Guide to Web Security

Learn about encryption fundamentals, envelope encryption, and how Capsule implements client-side decryption.

🔒 Premium Content
TierA

Understanding Cryptography Basics

A beginner-friendly introduction to symmetric and asymmetric encryption, and how the Web Crypto API makes it all accessible.

🔒 Premium Content
TierA

Zero Trust Architecture for APIs

How Zero Trust principles apply to API design and how DCA enables fine-grained cryptographic access control with independent tiers.

🔒 Premium Content
TierB

🔑 How the Demo Works

  1. First visit: Your browser generates an RSA key pair, stored securely in IndexedDB with extractable: false.
  2. Unlock Article: Returns a one-time contentKey — works for a single article, non-cacheable.
  3. Unlock Tier: Returns periodKeys derived via HKDF from the tier's contentName. Cached for 1 hour and reusable across all articles in the same tier.
  4. Cross-article unlock: Articles in the same tier share period keys, so unlocking TierA on one article auto-unlocks all TierA articles. TierB remains locked.

💡 Try this: Unlock "TierA" on one article, then open the other TierA article — it decrypts automatically! Then try the TierB article and notice it stays locked.