Building a Privacy-First URL Shortener on Blockchain

Source: Dev.to

Why Traditional URL Shorteners Are a Privacy Nightmare

• When you click a bit.ly link, here’s what happens:
  • Bit.ly logs your IP, timestamp, user agent
  • They see the destination URL
  • They track your browsing patterns
  • They sell this data to advertisers
• Even if you trust the shortener, their database can be hacked.

I built cryptly to solve this problem using blockchain and encryption.

Encryption (Client‑Side)

const encrypted = await crypto.subtle.encrypt(
  { name: "AES-GCM", iv: iv },
  key,
  urlBuffer
);

Blockchain Storage

• Encrypted URL stored on Cronos blockchain
• Immutable, decentralized
• No centralized database to hack

Decryption (Browser)

• Browser fetches from blockchain
• Decrypts locally using Web Crypto API
• Server never sees the destination

Tech Stack

• Cloudflare Workers (serverless, edge deployment)
• Web Crypto API (native browser encryption)
• Cronos blockchain (decentralized storage)

Privacy Benefits

• ✅ Server never sees destination URLs
• ✅ No tracking, no analytics
• ✅ No database to leak
• ✅ Censorship‑resistant (blockchain)

Live Demo

cryptly.workers.dev

Still in early stages but feedback welcome!

privacy #blockchain #webdev #opensource