PrivyNote - E2E Encrypted Secret Sharing

PrivyNote is a minimalist, open-source platform for sharing encrypted notes that self-destruct after being read. It features end-to-end encryption, ensuring that even the server never sees the plaintext content of your notes.

Features

• E2E Encryption: AES-GCM (256-bit) encryption performed entirely in the browser.
• Zero-Knowledge: The server stores only the ciphertext. The encryption key is never transmitted.
• Self-Destruction: Notes are deleted immediately after being read (optional).
• Expiration: Notes automatically expire after a set duration (10m, 1h, 1d, 7d).
• Rate Limiting: Protection against abuse.
• Privacy First: No tracking, no ads, no cookies, no localStorage.

Tech Stack

• Framework: Next.js (App Router)
• Database: PostgreSQL
• ORM: Prisma
• Ciphers: WebCrypto API
• Styling: Tailwind CSS

Local Development

1. Clone the repository
2. Install dependencies:

   npm install

3. Setup Environment: Create a .env file based on .env.example:

   DATABASE_URL="postgresql://user:password@localhost:5432/privnote?schema=public"

4. Run Database:

   docker-compose up -d db

5. Apply Migrations:

   npx prisma migrate dev

6. Start Dev Server:

   npm run dev

Docker Deployment

To run the entire stack with Docker:

docker-compose up --build

The application will be available at http://localhost:3000.

Security Considerations

• Key in Fragment: The encryption key is stored in the URL fragment (#). Fragments are not sent to the server by browsers, maintaining zero-knowledge.
• Token Hashing: The public identifier (token) is hashed using SHA-256 before being stored in the database.
• Memory Safety: Ciphertext is handled as JSON payloads. Plaintext only exists in the client's memory during encryption/decryption.