Server Implementation
The Zeno Server (Backend) is the authority that issues challenges and verifies proofs.
Cloudflare Worker
We use Cloudflare Workers for their global distribution and low latency. The server:
- Generates Challenges: Generates a random Discriminant (for VDF) and Seed (for Graph).
- Stores State: Uses R2 to store active challenge metadata with a short TTL.
- Verifies: Checks the Cuckatoo Cycle and VDF Proof.
- Prevents Replay: Deletes the challenge from storage immediately upon redemption attempt.
Security Features
- Origin Check: Validates the
Origin and Referer headers match allowed domains.
- IP Bans: Automatically bans IPs exceeding rate limits for 24 hours via R2.
- Time-Boxing: Challenges expire after a set time (default 60 seconds) to prevent hoarding.
API Specification
See Architecture for endpoint details.