Skip to main content

Cloud Sticky Note Tutorial

Overview​

The Cloud Sticky Note system is a secure, zero-backend solution for creating and sharing encrypted notes and files. This application provides end-to-end encryption with shareable links, supporting both text content and file attachments without requiring server-side storage.

Key Features​

  • End-to-End Encryption: AES-256 encryption for maximum security
  • Zero-Backend Architecture: No server storage required for note content
  • Shareable Links: Encrypted payloads embedded in URL fragments
  • File Attachment Support: Secure file sharing with encryption
  • Local Storage Option: Optional browser storage for convenience
  • Password Protection: Optional password-based encryption keys
  • Cross-Device Compatibility: Notes accessible from any modern browser

Quick Start​

1. Access the Application​

Visit in your browser: /app/cloudnote

2. System Requirements​

  • Modern Web Browser: Chrome, Firefox, Safari, or Edge with JavaScript support
  • Internet Connection: Required for initial page load (notes work offline)
  • URL Sharing Capability: For sharing encrypted note links

Detailed Usage Steps​

Step 1: Note Creation​

  1. Note Information Setup

    • Note Name: Descriptive identifier for the note
    • Content: Main text content of the note
    • File Attachments: Optional file uploads (images, documents, etc.)

  2. Security Configuration

    • Password Protection: Optional password for additional security
    • Encryption Method: Automatic AES-256 encryption
    • Key Generation: Random encryption key generation

  1. Automatic Encryption Process

    • Content encrypted before leaving the browser
    • Encryption key embedded in URL (if no password)
    • Password-derived keys for enhanced security

  2. Shareable Link Creation

    • URL format: https://.../app/cloudnote#note=<encrypted_payload>
    • Contains all note data in encrypted form
    • No server-side storage of sensitive information

Step 3: Note Sharing and Access​

  1. Link Distribution

    • Copy generated URL to share with recipients
    • URL contains everything needed to decrypt and view note
    • Recipients need only the URL (and password if set)

  2. Note Access

    • Recipients open URL in any modern browser
    • Automatic decryption using embedded key
    • Password prompt if password protection enabled

Step 4: Optional Local Storage​

  1. Browser Storage

    • Optional local storage for frequently accessed notes
    • Encrypted storage in browser's local storage
    • Accessible by note name without URL sharing

  2. Multi-Device Synchronization

    • Optional backend integration for device synchronization
    • Encrypted payload storage with name-based retrieval
    • Requires backend service configuration

Technical Specifications​

Encryption Protocol​

AES-256 Encryption​

  • Algorithm: Advanced Encryption Standard with 256-bit keys
  • Mode: CBC (Cipher Block Chaining) mode
  • Key Derivation: PBKDF2 with random salt
  • Initialization Vector: Random IV for each encryption

Key Management​

  • Random Key Generation: Cryptographically secure random keys
  • Password-based Keys: PBKDF2 derivation from user passwords
  • Key Storage: Embedded in URL or derived from password
  • Key Rotation: New key for each note creation

Data Format​

URL Structure​

https://domain.com/app/cloudnote#note=<base64_encoded_payload>

Payload Structure​

{
  "version": "1.0",
  "name": "Note Name",
  "content": "Encrypted content",
  "files": ["Encrypted file data"],
  "salt": "Random salt for key derivation",
  "iv": "Initialization vector for AES",
  "timestamp": "Creation timestamp"
}

Security Features​

Zero-Knowledge Architecture​

  • No Server Access: Encryption/decryption occurs client-side only
  • URL-based Sharing: All data contained in shareable link
  • Ephemeral Storage: No persistent server storage of sensitive data

Privacy Protection​

  • Metadata Minimization: Minimal identifying information in URLs
  • Forward Secrecy: Each note uses unique encryption keys
  • Access Control: Password protection for sensitive notes

Best Practices​

Security Considerations​

  1. Password Management

    • Use strong, unique passwords for sensitive notes
    • Share passwords through secure channels
    • Consider password managers for complex passwords

  2. Link Sharing Security

    • Share URLs through secure communication channels
    • Consider link expiration for time-sensitive information
    • Use password protection for sensitive content

  3. Data Sensitivity Assessment

    • Evaluate sensitivity before using cloud sharing
    • Consider alternative methods for highly sensitive data
    • Use appropriate security measures based on content

Usage Scenarios​

Research Collaboration​

  • Share research notes and preliminary findings
  • Collaborate on document drafts
  • Distribute meeting notes and action items

Project Management​

  • Share project specifications and requirements
  • Distribute task lists and progress updates
  • Collaborate on documentation and reports

Personal Organization​

  • Create encrypted personal notes
  • Share information across personal devices
  • Secure storage of sensitive personal data

Data Management​

  1. Note Organization

    • Use descriptive note names for easy identification
    • Maintain consistent naming conventions
    • Archive or delete notes when no longer needed

  2. Version Control

    • Create new notes for significant updates
    • Maintain version history through note naming
    • Document changes in note content

  3. Backup Strategies

    • Save important notes locally
    • Use multiple sharing methods for critical information
    • Consider printed copies for essential data

Troubleshooting​

Common Issues​

1. Link Access Problems

  • Verify URL is copied completely and accurately
  • Check browser compatibility and JavaScript support
  • Ensure network connectivity for initial page load

2. Decryption Failures

  • Verify correct password entry (case-sensitive)
  • Check URL integrity (no truncation or modification)
  • Ensure browser supports required cryptographic functions

3. File Attachment Issues

  • Check file size limits for browser compatibility
  • Verify supported file types for attachment
  • Ensure sufficient system memory for large files

Performance Optimization​

For Large Notes

  • Consider splitting large content into multiple notes
  • Use text compression for extensive text content
  • Optimize file attachments for web sharing

For Mobile Devices

  • Use responsive design for mobile accessibility
  • Optimize for limited mobile browser capabilities
  • Consider data usage for large attachments

Technical Support​

If you encounter technical issues:

  1. Check browser console for error messages
  2. Verify URL structure and completeness
  3. Ensure browser supports modern cryptographic functions
  4. Contact support with specific error details and browser information

Browser Compatibility​

  • Chrome 60+: Full support with modern cryptographic APIs
  • Firefox 55+: Complete functionality with Web Crypto API
  • Safari 11+: Support for required encryption standards
  • Edge 79+: Full compatibility with modern standards

Author: Liangchao Deng, Ph.D. Candidate, Shihezi University / CAS-CEMPS
This tutorial applies to Cloud Sticky Note System v1.0 Optimized for secure, decentralized note sharing and collaboration